Color-Coded Safety Glossary

First Aid/CPR - Health/Well-being - Home and Workplace Safety - Lifeguarding/Water Safety - Swimming/Aquatics

A-B     C-D     E-F     G-H     I-J     K-L     M-N     O-P    Q-R     S-T     U-V     W-X-Y-Z

C

cadence

The beat or measure of rhythmic motion or activity. For example, the flutter kick can have a 2-, 4-, or 6-beat cadence.

caffeine

An alkaloid found in tea and coffee that acts as a stimulant and a diuretic. Caffeine is sometimes added to soft drinks and energy pills and beverages.

Because coffee is a stimulant, it is not recommended by some first aid protocols as a beverage to rewarm a hypothermic victim. For example, in the American Red Cross Emergency Response textbook, page 382, it states as part of the care for hyppthermic victims: “Give warm, not hot, liquids that do not contain alcohol or caffeine if the patient is alert and able to swallow.” Alcoholic and caffeinated beverages may speed up heat loss despite the warm feeling they provide. (The hypothermia.org website suggests that while warm liquids are not effective with patients that are severely hypothermic, they may raise the morale of mildly hypothermic patients.)

calcium carbonate

A crystalline compound that can form on plumbing and pool surfaces when calcium hardness, pH, or total alkalinity are too high. This formation is also called scale.

calcium chloride

A soluble, white salt used to raise the calcium hardness level of swimming pool water.

calcium hardness

A measure in parts per million (ppm) of the calcium content of swimming pool water.

calcium hypochlorite

A yellow-white solid form of chlorine used in swimming pool water as a disinfectant/sanitizer.

calorie

A unit of heat equal to the amount of heat necessary to raise 1 gram of water by 1° Celsius (C) from 14.5° C to 15.5° C. Although the joule has replaced the calorie as the preferred measurement of heat energy in many scientific fields, the calorie remains a common measurement of food energy.

cancer

A collection of related diseases in which some of the cells of the body begin to divide without stopping and spread to surrounding tissues. Cancer can start anywhere in the body, which is made up of trillions of cells. As cells become more and more abnormal, old or damaged cells survive when they should die, and new cells form when they are not needed. These extra cells can divide without stopping and may form growths called tumors. Cancerous tumors are malignant, which means they can spread into, or invade, nearby tissues. In addition, as these tumors grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymph system and form new tumors far from the original tumor. For more information about cancer, go to the National Cancer Institute or the CDC Cancer Prevention and Control page.

canoe

A long, tight, narrow boat with curves sides and keen ends, usually propelled by hand paddle. Boating safety is part of water safety-safety in, on, and about the water.

canoe scull

A prone scull designed to move the swimmer headfirst, performed with arms at the sides by making figure-eight movements with the hands while turning palms toward the feet.

capacity

(1) The total number of individuals in the swimming pool area. (2) The total number of gallons in a swimming pool.

capalene

A synthetic fabric used next to the skin (base layer) when dressing for the cold. The purpose of the base layer of clothing is to keep the wearer dry by not absorbing sweat into the fabric but rather transporting it to outer surface where it can evaporate. To read about all 3 layers of winter clothing, go to clothing layers.

capillary

Any of the microscopically small blood vessels between arteries and veins that distribute oxygenated blood to tissue in the body.

capillary refill

A quick test for determining blood flow to tissue performed by lightly pinching a patient’s fingertip to apply pressure to the nail bed. (For an infant, apply light pressure to the patient’s arm or leg.) When the nail bed or skin blanches (turns white due to lack of blood), pressure is released to see how quickly color (blood) returns. Blood flow is adequate if color returns within 2 seconds or the time it takes to say “capillary refill.” This capillary refill test should be performed whenever a bandage or splint is applied to an extremity or whenever dehydration or shock is suspected.

To watch how this is done, check out this capillary refill video.

carbohydrates

Nutrients in food that are converted into glucose to provide the cells of the body with energy. Carbohydrates include foods with naturally occurring sugars such as whole grains, beans, vegetables, and fruits as well as less healthy foods with added sugars such as cakes, soda, and candy.

To determine the number of grams of carbohydrates needed each day, calculate 45% to 65% of your total calorie intake and divide by 4. For example, if you eat a 2,000-calorie diet, shoot for 225 to 325 grams of carbs per day; and if you eat 2,500 calories a day, aim for 281 to 406 grams of carbs. Adults who drop their intake to 1,200 calories a day for weight loss need about 50 percent of their calories from carbs, or 150 grams per day.

Although carbs should make up the majority of your calorie intake, limit “bad” carbs — such as refined grains and added sugars — as much as possible since they provide calories but few additional nutrients. According to the American Heart Association, men should limit added sugars to 9 teaspoons, or 150 calories, per day and women should eat no more than 6 teaspoons, or 100 calories, from added sugars each day. These extra sugars are present in desserts, sweets, syrups, pastries, many granola bars, sodas and other sugary beverages. Refined grains are in foods such as white bread and white rice.

Meeting your daily carb requirements with healthy carbs, instead of refined grains and sugars, will help you maintain a healthy body weight and boost your energy level. Examples of nutritious carbs include whole grains, fruits, vegetables, legumes, low-fat milk, low-fat yogurt, nuts and seeds.

carbon dioxide

A naturally occurring chemical compound composed of one carbon atom and two oxygen atoms, existing as a gas in the atmosphere at a concentration of about 392 ppm. As part of the carbon cycle of photosynthesis, plants, algae, and cyanobacteria absorb carbon dioxide, light, and water to produce carbohydrate energy for growth and reproduction and expel oxygen as a waste product. Carbon dioxide is toxic at higher concentrations: a 1% concentration (10,000 ppm) can make individuals feel drowsy and a 7% to 10% concentration (70,000 to 100,000 ppm) can cause dizziness, headaches, visual and hearing dysfunction, and unconsciousness.

carbon monoxide

A colorless, odorless, tasteless gas consisting of one carbon atom and one oxygen atom that is highly toxic at higher concentrations. Carbon monoxide forms from the partial oxidation of carbon-containing compounds (i.e., when insufficient oxygen is present to produce carbon dioxide, such as when operating a stove or internal combustion engine in a confined space). Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide combines with hemoglobin to form carboxyhemoglobin, which is inefficient in delivering oxygen to body tissues. Concentrations as low as 667 ppm in the air can cause up to 50% of the body’s hemoglobin to convert to carboxyhemoglobin. A level of 50% carboxyhemoglobin can result in seizures, coma, and fatality. The short-term effects of carbon monoxide poisoning are cumulative since the half-life is about 5 hours in fresh air. Carbon monoxide is also known as carbonous oxide or carbonyl.

carbonous oxide

Another name for carbon monoxide.

carbonyl

Another name for carbon monoxide.

carboxyhemoglobin

Red blood cells (hemoglobin) that have carbon monoxide bound to them instead of oxygen. Carbon monoxide has a much stronger binding to hemoglobin than to oxygen. Carboxyhemoglobin is formed in carbon monoxide poisoning and leads to oxygen deficiency in the body. The level of carboxyhemoglobin is a measure of the extent of carbon monoxide exposure. A level of 50% carboxyhemoglobin can result in seizures, coma, and fatality.

carbuncle

An abscess made up of multiple boils that extend into the deeper layers of the skin. Boils and carbuncles are often caused by the bacteria staphylococcus aureus. This type of infection can be contagious and may spread to other parts of the body or to other persons.

Carbuncle cross section illustration courtesy of WebMD.

carcinogen

A chemical, physical, or biological agent that can cause cancer in humans or animals.

cardiac

Pertaining to the heart.

cardiac arrest

An abrupt loss of heart function in a person who may or may not have diagnosed heart disease. The time and mode of death are unexpected. It occurs instantly or shortly after symptoms appear. Each year, more than 420,000 EMS-assessed, out-of-hospital cardiac arrests occur in the United States.

The term heart attack is often mistakenly used to describe cardiac arrest. While a heart attack may cause cardiac arrest and sudden death, the terms do not mean the same thing. Heart attacks are caused by a blockage that stops blood flow to the heart. A heart attack (or myocardial infarction) refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in the death of the heart attack victim.

Cardiac arrest is caused when the heart’s electrical system malfunctions. In cardiac arrest, death results when the heart suddenly stops working properly. This may be caused by abnormal, or irregular, heart rhythms (called arrhythmias).

A common arrhythmia in cardiac arrest is ventricular fibrillation. This is when the heart’s lower chambers suddenly start beating chaotically and don’t pump blood. Death occurs within minutes after the heart stops. Cardiac arrest may be reversed if CPR (cardiopulmonary resuscitation) is performed and a defibrillator is used to shock the heart and restore a normal heart rhythm within a few minutes.

For more information about cardiac arrest, go to the American Heart Association Cardiac Arrest page.

cardiogenic shock

A type of medical shock that occurs when the heart is unable to supply adequate blood circulation to vital organs due to heart disease or an injury to the heart muscle.

cardiopulmonary resuscitation (CPR)

An emergency lifesaving procedure performed when a person stops breathing or the heart stops beating. It can be performed as compression-only CPR with rapid compressions on the chest, or it can be performed as chest compressions and ventilations (sometimes called “conventional” CPR). Immediate high-quality CPR can double or triple chances of survival after sudden cardiac arrest. Click the link to learn more about high-quality CPR.

cardiovascular

Pertaining to the heart and blood vessels. The circulatory system of the heart and blood vessels is the cardiovascular system.

CARE procedures

A protocol in the YMCA Lifeguarding program for handling a scuba diving emergency in which CARE stands for:

• Cognizance-Be aware when a scuba diver is in trouble, including no moving, struggling, removing mask and snorkel at the surface in an effort to breathe, clinging to another diver or any object to help remove them from the water, etc.
• Assessment-Determine the nature of the problem, the status of the diver in trouble, the availability of rescue personnel and equipment, etc.
• Rescue-Activate the emergency medical services (EMS) system, approach the diver, use an appropriate rescue for an active or passive victim with a rescue tube, release the diver’s weight belt and inflate the buoyancy compensator (BC), tow the diver to safety, and monitor the diver’s level of consciousness and breathing.
• Evacuation-Assume a diver having breathing problems, confusion, convulsions, and/or paralysis is suffering from decompression sickness. The diver must be kept lying flat while be transported to the medical facility. If vomiting occurs, roll the diver onto one side to allow the vomit to drain out of the mouth and airway. Maintain an open airway, and administer medical oxygen if it is available and you are trained to use it.

carotid arteries

Major blood vessels in the neck that supply blood to the brain, neck, and face. There are two carotid arteries, one on the right and one on the left.

catastrophic reaction

Behaviors (e.g., screaming, striking out, etc.) exhibited by patients who are overwhelmed by the dire or horrific circumstances of a disaster or emergency.

CBRNE

An acronym used by the US Department of Homeland Security to describe the main types of weapons of mass destruction: chemical, biological, radiological/nuclear, and explosive.

cell

The basic structural, functional, and biological unit of all known living organisms. Cells, sometimes known as the building blocks of life, are the smallest unit of life that can replicate independently.

Each cell is a small container of chemicals and water wrapped in a membrane. There are 100 trillion cells in a human body, each with all of the genetic information necessary to recreate that human being. This information is encoded within the cell nucleus in 6 billion subunits of DNA called base pairs. These base pairs are packaged in 23 pairs of chromosomes, with 1 chromosome in each pair coming from each parent. Each of the 46 human chromosomes contains the DNA for thousands of individual genes.

Cells in the human body specialize and group together with other similar cells to form tissues. Tissues, in turn, form organs, and organs and tissues work together as body systems to complete functions vital to the body’s health and well-being.

cerebral

Pertaining to the brain.

cervical collar

A neck brace made of soft or rigid material designed to support the patient’s head and neck. Also called a c-collar. Various sizes of cervical collars are typically included in a set so that the correct size can be available for different size patients.

The 2015 American Red Cross and American Heart Association Guidelines for First Aid strongly recommend against the use of cervical collars by first aid providers. Potential adverse effects from the use of a cervical collar by first aid providers include increased intracranial pressure and potential airway compromise. No studies were found that demonstrated a decrease in neurologic injury with the use of a cervical collar.

chain of command

The levels of authority in the company or organization from the top position, such as a CEO or business owner, down to workers on the front line. Companies institute a chain of command to provide workers at all levels with a supervisor to whom they may ask questions or report problems.

The chain of command establishes the organization hierarchy. Business owners or CEOs occupy the top position in a company hierarchy, which is also the top spot in a chain of command. Vice presidents and upper management employees report directly to the owner of the company or chief executive officer. Supervisors or department managers report to higher-level managers, and workers report to supervisors and department managers. Each company establishes its own hierarchy or organizational structure, which is the basis for a chain of command. All employees in the organization recognize the structure of the company when following a chain of command.

Each employee on the chain of command is responsible for a particular area of the business. For example, operations supervisors or managers must ensure that workers complete production tasks and activities, while upper-management employees establish the high-level direction the company takes. For example, an operations director may develop a plan to reduce lead time in production by two days, but supervisors directing the activities of production workers execute the high-level plan. When a worker doesn’t follow the established chain of command, he undermines the authority of his direct supervisor.

An established chain of command creates efficiency when reporting problems or communicating with workers. For example, when a worker communicates a problem to his supervisor’s manager, the supervisor doesn’t have an opportunity to correct the problem. Managers, while familiar with higher-level strategies and planning, aren’t prepared to correct operational issues or the day-to-day activities of front-line employees. It’s more efficient to direct complaints or report problems to the supervisor or manager at the lowest level before escalating the issue to upper-management employees.

When employees frequently ignore the chain of command, it may affect the morale of supervisors and managers. Companies without a clear chain of command can create an atmosphere of uncertainty and chaos, which affects the morale of all workers in the organization. Poor company morale may lead to high employee turnover and lower productivity.

chains of survival

The steps (or “links”) critical to improving the chances of survival and recovery for victims of sudden cardiac arrest. For out-of-hospital cardiac arrests (OHCA), the links in the cardiac chain of survival are:

• Early recognition of sudden cardiac arrest and activation of the emergency response system (calling 9-1-1).
• Immediate high-quality CPR.
• Rapid defibrillation.
• Basic and advanced EMS.
• Advanced cardiovascular life support and post–cardiac-arrest care.

For in-hospital cardiac arrest (IHCA), the links in the cardiac chain of survival are slightly different as follows:

• Appropriate surveillance and prevention of cardiac arrest.
• Prompt detection and notification of cardiac arrest.
• Immediate high-quality CPR.
• Rapid defibrillation.
• Advanced cardiovascular life support and post–cardiac-arrest care.

chemical identity

A name that uniquely identifies a substance. 

chest pain

A warning sign of a heart attack. It can feel like uncomfortable pressure, squeezing, or fullness. If you feel this kind of chest pain or other heart attack warning signs, call 9-1-1. Another type of chest pain that occurs during physical activity and subsides with rest is called stable angina. Stable angina can usually be managed with medication, but a heart attack is a medical emergency.

child

For the purposes of receiving emergency medical treatment or first aid, a person at least 1 year old to the onset of puberty (around 10 to 14 years old).

child abuse

Any action that results in physical or psychological harm to a child, including the infliction of physical injury, sexual abuse, or emotional distress.

childhood asthma

The most common serious chronic disease in infants and children. Also known as pediatric asthma. In infants and children, asthma may appear as:

• Wheezing (whistling sound) when breathing
• Coughing
• Rapid breathing
• Labored breathing
• Complaints of chest hurting 
• Reduced energy
• Feeling weak or tired

Some children have symptoms only when exercising or playing a sport. This is called exercise-induced bronchospasm.

Childhood asthma, just like asthma in adults, cannot be cured. But with the right medications and treatment plan, symptoms can be controlled. This is extremely important in order to prevent damage to growing lungs.

Risk factors for developing childhood asthma include:

• Allergies
• Family history of allergies and/or asthma
• Frequent respiratory infections
• Low birth weight
• Second-hand smoke before and/or after birth
• Growing up in a low income, urban environment

child neglect

One of the most frequently reported types of child abuse caused when a parent or guardian fails to provide necessary, age-appropriate care to a child.

chlorine

A chemical element with symbol Cl and atomic number 17. It also has a relative atomic mass of 35.5. Chlorine is in the halogen group (17) and is the second lightest halogen following fluorine. The element is a yellow-green gas under standard conditions, where it forms diatomic molecules. Chlorine has the highest electron affinity and the third highest electronegativity of all the reactive elements. For this reason, chlorine is a strong oxidizing agent. 

Chlorine was first recognized as a gas around 1630. Then, in 1774, elemental chlorine was first prepared and studied by Swedish chemist Carl Wilhelm Scheele. Throughout the 1800s, chlorine began to be used as a bleaching and disinfecting agent. By 1918, the US Department of Treasury called for all drinking water to be disinfected with chlorine. Chlorine is presently an important chemical for water purification (such as in water treatment plants), in disinfectants, and in bleach. Chlorine in water is more than three times as effective as a disinfectant against Escherichia coli than an equivalent concentration of bromine, and is more than six times more effective than an equivalent concentration of iodine.

Chlorine is usually used (in the form of hypochlorous acid) to kill bacteria and other microbes in drinking water supplies and public swimming pools. In most private swimming pools, chlorine itself is not used, but rather sodium hypochlorite, formed from chlorine and sodium hydroxide, or solid tablets of chlorinated isocyanurates. The main drawback of using chlorine in swimming pools is that the chlorine reacts with the proteins in human hair and skin. Once the chlorine reacts with the hair and skin, it becomes chemically bonded. 

Chlorine is a toxic gas that irritates the respiratory system. Because it is denser than air, it tends to accumulate at the bottom of poorly ventilated spaces. Chlorine gas is a strong oxidizer, which may react with flammable materials.

Chlorine is detectable with measuring devices in concentrations of as low as 0.2 parts per million (ppm), and by smell at 3 ppm. Coughing and vomiting may occur at 30 ppm and lung damage at 60 ppm. About 1000 ppm can be fatal after a few deep breaths of the gas. The IDLH (immediately dangerous to life and health) concentration is 10 ppm. Breathing lower concentrations can aggravate the respiratory system, and exposure to the gas can irritate the eyes. The toxicity of chlorine comes from its oxidizing power. When chlorine is inhaled at concentrations above 30 ppm, it begins to react with water and cells, which change it into hydrochloric acid (HCl) and hypochlorous acid (HClO).

When used at specified levels for water disinfection, the reaction of chlorine with water is not a major concern for human health. Other materials present in the water may generate disinfection by-products that are associated with negative effects on human health. Despite this risk, the World Health Organization has stated that “the risk of death from pathogens is at least 100 to 1,000 times greater than the risk of cancer from disinfection by-products (DBPs)” {and} the “risk of illness from pathogens is at least 10,000 to 1 million times greater than the risk of cancer from DBPs.”

choking

The inability to breathe because the trachea is blocked, constricted, or swollen shut. According to the American Red Cross, more than 3000 people die from choking each year in the United States.

cholesterol

A soft, waxy substance found among the lipids (fats) in the bloodstream and in all the body’s cells. There are several kinds, but the most important are low-density lipoprotein (LDL or “bad”) and high-density lipoprotein (HDL or “good”). Too much LDL cholesterol can increase risk for heart disease, stroke, and other cardiovascular diseases.

chronic

An illness or condition persisting for a long time or constantly recurring. Compare with acute.

chronic cough

A cough present for 8 weeks or more. The most common causes of chronic cough are postnasal drainage, asthma, and gastroesophageal reflux disease (GERD), also known as heartburn. 

chronic effect

A health effect that occurs over a long period of time as a result of continued or periodic exposure to the offending agent.

chronic obstructive pulmonary disease (COPD)

A group of lung diseases (including emphysema and chronic bronchitis) that block airflow in the lungs. This makes it increasingly difficult to breathe. Many of the symptoms of COPD are similar to asthma symptoms. Although COPD is the leading cause of death and illness worldwide, it is often preventable. That is because long-term cigarette smoking is the primary cause of this life-threatening disease. Additionally, smokers are particularly likely to suffer from a combination of both asthma and COPD. It is important to distinguish between asthma, COPD or a combination of the two, as the treatment approach will differ.

Inside the lungs, COPD can clog the airways and damage the tiny, balloon-like sacs (alveoli) that absorb oxygen. These changes can cause the following symptoms:

• Shortness of breath in everyday activities
• Wheezing
• Chest tightness
• Constant coughing

When a person has emphysema, a type of COPD, the delicate air sacs in the lungs called alveoli, cannot expand and contract properly. In time, the damage destroys the air sacs, leaving large holes in the lungs, which trap stale air. People with emphysema can have great trouble exhaling.

Severe COPD can make it difficult to walk, cook, clean house, or even bathe. Coughing up excess mucus and feeling short of breath may worsen. Advanced illness can also cause:

• Swollen legs or feet from fluid buildup
• Weight loss
• Less muscle strength and endurance

To learn more about COPD, follow these links:

• COPD (American Lung Association)
• COPD (Mayo Clinic)
• What Is COPD? (COPD Foundation)

circle swimming

A technique for sharing a lane during lap swimming or training in which two or more swimmer stay to the right as close to the lane line as possible, creating an elongated, counterclockwise circle pattern within the lane that allows for swimming in both directions. Circle swimming etiquette includes selecting lanes and swimming partners who are performing similar types of workout at similar speeds, use an agreed upon passing signal (like a tap on the foot).

circulation

Circulation is the pumping of blood from the heart throughout the body through a system of blood vessels composed of arteries and veins.

circulatory system

Body system consisting of the heart, blood vessels, blood, lymph nodes, lymph vessels, and lymph. 

clinical death

The condition of a patient who shows no signs of life (i.e., no movement, breathing, or pulse). In this condition, a patient who receives effective basic and advanced life support may recover fully. Every second counts. Without prompt and effective care, clinical death can progress to biological death (i.e., irreversible damage to brain cells) in as little as 4 minutes. Following biological death, signs of obvious death occur over time.

clot

(n) A small coagulated mass of blood. (v) To undergo chemical changes that result in converting fluid blood into a coagulated mass for sealing openings in blood vessels. For more information, see clotting below.

clothing layers

A method of dressing for comfort and insulation in the cold, consisting of 3 layers:

• A base layer of wool or capalene to keep the wearer dry.
• An insulating layer of wool or fleece to protect the wearer from the cold.
• An outer layer (shell layer) of a waterproof, breathable fabric (e.g., eVent®, Gor-Tex®, MemBrain®, Strata®, Sympatex®, or equivalent) to protect the wearer from wind, rain, and snow.

This is included in first aid and water safety education programs to prevent hypothermia in and out of the water.

clotting

The process by which blood thickens at a wound site to seal the opening in the blood vessel and stop the bleeding (also known as coagulation). Blood clotting is included in hemostatis. Hemostasis is the body’s way of stopping injured blood vessels from bleeding.

Too much clotting can block blood vessels that are not bleeding. Consequently, the body has control mechanisms to limit clotting and dissolve clots that are no longer needed. An abnormality in any part of this system that controls bleeding can lead to excessive bleeding or excessive clotting, both of which can be dangerous. When clotting is poor, even a slight injury to a blood vessel may lead to severe blood loss. When clotting is excessive, small blood vessels in critical places can become clogged with clots. Clogged vessels in the brain can cause strokes, and clogged vessels leading to the heart can cause heart attacks. Pieces of clots from veins in the legs, pelvis, or abdomen can travel through the bloodstream to the lungs and block major arteries there (pulmonary embolism).

coagulation

See clotting above.

cognition

The set of all mental abilities and processes related to knowledge, attention, memory, judgment, reasoning, problem solving, decision making, comprehension and production of language, etc. Human cognition is conscious and unconscious, concrete or abstract, as well as intuitive (like knowledge of a language) and conceptual (like a model of a language). Cognitive processes use existing knowledge and generate new knowledge.

cognitive

Having to do with thinking or thought processes.

cognitive impairment

A diminished capacity to use thought processes such as memory, judgment, reasoning, problem solving, decision making, language, etc. Mild cognitive impairment (MCI) is an intermediate stage between the expected cognitive decline of normal aging and the more serious decline of dementia. If you have mild cognitive impairment, you may be aware that your memory or mental function has “slipped.” Your family and close friends also may notice a change. But generally these changes aren’t severe enough to interfere with your day-to-day life and usual activities.

Mild cognitive impairment may increase your risk of later progressing to dementia, caused by Alzheimer’s disease or other neurological conditions. But some people with mild cognitive impairment never get worse, and a few eventually get better.

cold-water immersion

A life-threatening event that affects victims in four phases:

• Cold shock response-This lasts only about 1 minute and refers to the effect cold water has on the ability to breathe. When victims fall into the water, there is an immediate gasp reflex in response to rapid skin cooling. If the victims are underwater, they may breathe in and take water into their lungs and never resurface. This is called the sudden immersion syndrome. If victim manage to return to the surface, they will experience hyperventilation and vasoconstriction of the arteries. Breathing is compromised and the heart must work harder, so cardiac arrest can occur.
• Cold incapacitation-This occurs after 5 to 15 minutes in cold water. The combination of the cold temperature and the lack of blood flow to the extremities cause them to stop working properly. Victims will not be able to grab an object, swim, or stay afloat. If victims are not wearing a life jacket, drowning can occur.
• Hypothermia—Hypothermia does not set in for at least 30 minutes in cold water. If victims are wearing a life jacket, they may survive the effects of mild, moderate, and severe hypothermia which eventually leads to cardiac arrest after hours in the water. HELP and huddle techniques in cold water may prolong survival time in cold water.
• Post-rescue collapse-Victims can experience life-threatening problems even when the rescue is in progress. Once rescue is imminent or has just taken place, a mental relaxation occurs, creating a decreased output of stress hormones that helps victims survive in cold water. Blood pressure can drop and muscles can fail, causing collapse and in some extreme cases, even cardiac arrest and death. The key thing to remember is that heart function is dramatically impacted by the way that a victim is handled and removed from the water. Handle the victim gently and rewarm carefully.

The importance of wearing a life jacket in, on, and around cold water cannot be overstated. It can mean the difference between drowning within minutes and surviving for over one hour. For more information about cold-water immersion, check out Beyond Cold Water Boot Camp or the Oregon State Marine Board.

cold zone

The outer perimeter of the zones most directly affected by an emergency involving hazardous materials. This is sometimes called the support zone or the normal operations zone. 

common law

The part of law (also called case law or precedent) derived from custom and judicial decisions made previously in similar situations rather than from statutes. Often contrasted with statutory law.

compact jump

A lifeguard entry from a low deck into shallow water or from a height of 3 feet or more into water at least 5 feet deep, performed by holding the rescue against the chest and jumping into the water with feet parallel to the surface of the water and knees bent and held together.

To see a demonstration of the compact jump, click Compact Jump Demo (Jackie Swift).

comparative negligence

A rule of law applied in negligence cases in which responsibility and damages are based on the proportional fault of every party directly involved. Compare with contributory negligence.

competence

The mental capacity of an individual to participate in legal proceedings or transactions, and the mental condition a person must have to be responsible for his or her decisions or acts. Competence is an attribute that is decision-specific.

complete airway obstruction

A blockage of the breathing passage to the degree that the patient cannot cough, speak, or breathe.

complex access

The use of specialized equipment to gain access to a patient for the purpose of extrication from a motor vehicle or other dangerous situation.

compression-only CPR

• Call 9-1-1 (or send someone to do that).
• Push hard and fast in the center of the chest. 

When you call 9-1-1, you need to stay on the phone until the 9-1-1 dispatcher (operator) tells you to hang up. The dispatcher will ask you about the emergency. They will also ask for details like your location. It is important to be specific, especially if you’re calling from a mobile phone as that is not associated with a fixed location or address. Remember that answering the dispatcher’s questions will not delay the arrival of help.

Click for a humorous PSA on compression-only CPR with Dr. Ken Jeong! Here’s a British version of the same message with Vinnie Jones! And another with Mini Vinnie!

compression

The pressing and releasing of the breastbone used to manually squeeze blood from the heart and pump it through the cardiovascular system of a patient who has suffered sudden cardiac arrest. Compressions are part of conventional and compression-only CPR.

compression fraction

The amount of time spent giving compressions to a patient in cardiac arrest, expressed as a percentage of total time spent with the patient. A compression fraction of at least 60% is desirable. If you have been caring for a patient for 5 minutes, a compression fraction of 60% means that 3 minutes of that care was spent giving the patient high-quality chest compressions. So, to express this mathematically: 3/5 = 0.6 (60%).

To achieve a high compression fraction:

• Start CPR immediately for all nonbreathing, pulseless patients.
• If you are unwilling or unable to give rescue breaths, give continuous chest compressions only until EMS personnel arrive. Rotate compressors every 2 minutes.
• Push hard and push fast in the center of the patient’s chest. Be sure to give high-quality CPR.
• Once you begin CPR, do not stop unless the patient shows obvious signs of life or EMS personnel arrive and tell you to stop.

concentration-time (CT) inactivation value

The number of minutes it takes to kill a particular pathogen in chlorinated water at 1 part per million (mg/L) of free chlorine with a pH of 7.5 or lower and a water temperature of 77° F (25° C) or higher. Here are the CT inactivation numbers for pathogens found in swimming pools and hot tubs:

• E. coli O157:H7 bacterium: 1
• Hepatitis A virus: 16
• Giardia parasite: 45
• Cryptosporidium parasite: 15,300

The CT inactivation can be used to calculate disinfection time at higher concentrations of free chlorine. For example, at 3 ppm of free chlorine residual, the Giardia parasite should be inactivated in about 15 minutes (although CDC literature calls out 19 minutes). 

These values determine the recommended protocols for disinfecting a swimming pool following a fecal incident. Although E. coli, hepatitis A, and Giardia pathogens may be in formed or diarrheal feces, Cryptoporidium only is present in diarrhea. Therefore, a formed-stool incident requires a shorter disinfection time based on the Giardia parasite (which has the largest CT inactivation value). A diarrheal incident, however, may contain Cryptosporidium, so the disinfection time must be longer and the chlorine concentration must be higher. At 20 ppm, the Cryptosporidium parasite will be inactivated in 15,300/20 = 765 minutes or 12.75 hours.

To learn more about CT inactivation, fecal incidents, and pathogens in swimming pools, go to the CDC’s Disinfection & Remediation of Pools & Hot Tubs.

concussion

A traumatic brain injury that changes the way your brain functions usually without any signs of brain damage visible on imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI). The effects of concussion are usually temporary but can include headaches and problems with concentration, memory, balance, and coordination. 

Although concussions usually are caused by a blow to the head, they can also occur when the head and upper body are violently shaken. This is especially true with infants and small children. These injuries can cause a loss of consciousness, but most concussions do not. Because of this, some people have concussions and don’t realize it.

Most concussive traumatic brain injuries are mild, and people usually recover fully. On the other hand, people who have concussions caused by sports activities are at risk of serious consequences, including repeated concussions and possibly permanent brain damage.

The signs and symptoms of a concussion can be subtle and not immediately apparent. Symptoms can last for days, weeks, or even longer. Common signs and symptoms of a concussion may include:

• Headache or a feeling of pressure in the head
• Temporary loss of consciousness
• Amnesia surrounding the traumatic event
• Dizziness or “seeing stars”
• Ringing in the ears
• Nausea
• Vomiting
• Slurred speech
• Delayed response to questions
• Appearing dazed or confused
• Fatigue

The AVPU Scale or the Glasgow Coma Scale can be used to help determine a significant head injury. Some symptoms of concussions, however, may be delayed in onset by hours or days after injury, such as:

• Concentration and memory complaints
• Irritability and other personality changes
• Sensitivity to light and noise
• Sleep disturbances
• Psychological adjustment problems and depression
• Disorders of taste and smell

Head trauma is very common in young children. But concussions can be difficult to recognize in infants and toddlers because they may not be able to describe how they feel. Nonverbal clues of a concussion may include:

• Appearing dazed
• Listlessness and tiring easily
• Irritability and crankiness
• Loss of balance and unsteady walking
• Crying excessively
• Change in eating or sleeping patterns
• Lack of interest in favorite toys

The American Academy of Pediatrics recommends that you call your child’s doctor for advice if your child receives anything more than a light bump on the head. If your child doesn’t have signs of a serious head injury, and if your child remains alert, moves normally and responds to you, the injury is probably mild and usually doesn’t need further testing. In this case, if your child wants to nap, it’s OK to let him or her sleep. If worrisome signs develop later, seek emergency care.

Experts recommend that an athlete with a suspected concussion not return to play until he or she has been medically evaluated by a health care professional trained in evaluating and managing concussions. Children and adolescents should be evaluated by a health care professional trained in evaluating and managing pediatric concussions. 

Seek emergency care (call 911 or see a doctor) for an adult or child who experiences a head injury and symptoms such as:

• Repeated vomiting
• A loss of consciousness lasting longer than 30 seconds
• A headache that gets worse over time
• Changes in his or her behavior, such as irritability
• Changes in physical coordination, such as stumbling or clumsiness
• Confusion or disorientation, such as difficulty recognizing people or places
• Slurred speech or other changes in speech

Other severe symptoms include:

• Seizures
• Vision or eye disturbances, such as pupils that are bigger than normal (dilated pupils) or pupils of unequal sizes
• Lasting or recurrent dizziness
• Obvious difficulty with mental function or physical coordination
• Symptoms that worsen over time
• Large head bumps or bruises on areas other than the forehead in children, especially in infants under 12 months of age

To care for a suspected concussion or head injury:

1. Call 911 or the local emergency number, especially if the head injury involves the signs and symptoms described above.
2. Have the patient rest. In a first aid situation, this means having the patient assume a position of comfort and limiting activities, physical exertion, and even mental concentration. If the patient is having memory problems, encourage the person not to stress about this but to rest mind and body.
3. Monitor consciousness and breathing. Be ready to give CPR if the patient stops breathing.
4. Care for shock by maintaining the patient’s normal body temperature, by staying with the patient, and by comforting and reassuring the patient.

For more information about concussions, follow these links:

• A Bang to the Brain: What We Know About Concussions (National Institutes of Health)
• Concussion (FamilyDoctor.org)
• Concussion (Mayo Clinic)
• Concussion (Merck)
• Concussion (WebMD)
• Conmoción cerebral (FamilyDoctor.org)-en español
• Heads Up (CDC)
• Sports-Related Concussion (Merck)

confidentiality

The ethical duty not to affirmatively disclose personal information obtained from a patient during the course of first aid treatment except as needed for medical reasons or as required by law.

consent

Permission to provide care given by an ill or injured person or, in the case of a child or infant, by the parent or legal guardian. To obtain consent, the first aid provider should state his/her name and level or training and ask to help. Informed consent is ongoing; that is to say, the first aid provider should continue to inform the patient about first aid measures to be taken. At any time that the patient feels uncomfortable, he/she can withdraw consent by refusing care.

In the case of an unresponsive patient or an unattended minor child, consent is implied, meaning that the first aid provider may proceed as if consent was given.

To read more about informed consent, check out Obtaining Informed Consent from Patients (NCBI) and The Process for Obtaining Informed Consent (WHO). For a legal perspective, go to Understanding Informed Consent - A Primer (FindLaw) and What Is Implied Consent? (LegalInfo).

constructive notice

The fiction that someone got notice even though actual notice was not personally delivered to that person. The law may provide that a public notice put on the courthouse bulletin board is a substitute for actual notice. Or the court may authorize service by publication when a spouse has left the state to avoid service in a divorce action. The legal advertisement of the summons in an approved newspaper is treated as constructive notice, just as if the summons and petition had been served personally. Compare with actual notice.

In the context of aquatic facility operation, if employees or program participants are aware of a hazardous condition but they fail to report it to the operator, the operator may be considered to have constructive notice of the hazard since the operator should have been aware of it and/or should have had reporting procedures in place to give actual notice of the hazard.

At a swimming pool, for example, the pool operator must ensure the following:

• Chemicals are safely and properly used, labeled, and stored.
• Ladders, diving structures, lighting, fixtures, pool area, and locker room areas are safe and in good repair.
• Rescue equipment is readily available and in good working order.
• Pool water is clean, clear, and properly filtered, disinfected, and pH balanced.
• Water depth is clearly marked and important rules are posted.
• Adequate lifeguard services are in place as required by law or policy.
• Lifeguards participate in adequate training for their job.
• Lifeguards actively and continuously scan the pool area, enforce rules and safety practices, and make rescues and administer first aid when needed. All incidents are reported in writing.
• All applicable laws for pool operation are followed.
• Regular checks for facility hazards are made and the results is reported in writing.

contact dermatitis

An inflammation of the skin resulting from direct contact of a substance with the skin. Unlike atopic dermatitis, there is not necessarily a predisposition to allergic disease.

Symptoms of contact dermatitis include: 

• Red rash, bumps or a burn-like rash on the skin
• Itchy, painful or burning skin
• Blisters and draining fluid

There are two types of contact dermatitis:

• Irritant contact dermatitis is the most common form and is caused when substances such as solvents or other chemicals irritate the skin. The exposure produces red, often more painful than itchy, patches on the involved skin areas.
• Allergic contact dermatitis occurs when a substance triggers an immune response. Nickel, perfumes, dyes, rubber (latex) products, topical medications, and cosmetics frequently cause allergic contact dermatitis. 

To learn more about contact dermatitis, follow these links:

• Contact Dermatitis (AAD)
• Contact Dermatitis (Mayo Clinic)
• Contact Dermatitis (WebMD)

contributory negligence

A doctrine of common law that if a person’s own negligence contributes to causing an accident in which that person is injured, the injured party can’t collect any damages (money) from another party who caused the accident. Because this doctrine often ended in unfair results (where a person only slightly negligent was prohibited from recovering damages from a person who was much more so), most states now use a comparative negligence test instead, in which the relative percentages of negligence by each person are used to determine how much the injured person recovers.

contusion

An injury to the soft tissues of the body usually caused by blunt force that results in minor blood vessel damage under the skin and the spreading of blood into surrounding tissue and the discoloration of the skin that may be reddish, black-and-blue, or greenish-yellow (also known as a bruise). When bleeding under the skin involves larger blood vessels, it can result in a large area of pooling blood called a hematoma or in continuous internal bleeding, which can be life-threatening. 

Cooper 12-Minute Swim Test

An age- and gender-adjusted swimming test of aerobic capacity and endurance, performed by having the swimming cover the greatest distance possible in 12 minutes using whatever stroke(s) are preferred and resting as necessary. A chart defines the following fitness categories based on age, gender, and distance swum: excellent, good, fair, poor, and very poor. To download the Cooper 12-minute swim chart, check out this University of Michigan lab sheet.

Some studies have been done that challenge the reliability of the Cooper Swim Test. One such study is here.

COPD

Chronic obstructive pulmonary disease.

corrosive

A chemical that causes visible destruction of, or irreversible alterations in, living tissue by chemical action at the site of contact.

cough CPR

The use of voluntary coughs every 1 to 3 seconds after the onset of a heart attack to generate blood flow and to prolong consciousness. This practice should be limited to environments where the patient is being monitored by health professionals; it should not delay conventional care.

counter-coop injury

A brain injury that occurs directly opposite to the initial point of impact. Compare with coup. Concussions can cause coup/counter-coop brain injuries.

coup injury

The point of initial impact of a brain injury. Compare with counter-coup, the impact of the brain against the skull in the opposite location from the point of impact. Concussions can cause coup/counter-coop brain injuries.

cramp

A painful, involuntary contraction of a muscle or muscle group, typically caused by dehydration, fatigue, strain, or lack of oxygen. Though generally harmless, muscle cramps can make it temporarily impossible to use the affected muscle.

Long periods of exercise or physical labor, particularly in hot weather, may lead to muscle cramps. Some medications and certain medical conditions also may cause muscle cramps. You can usually treat muscle cramps at home with self-care measures.

For swimmers, most cramps occur in the calf, foot, or hand since these are the most active parts and the farthest parts from the heart. Sometimes abdominal muscles can tighten as well, causing a side ache. In addition to the sudden, sharp pain, you may also be able to feel or see a hard lump of muscle tissue beneath your skin.

To alleviate a cramp, have the patient stretch the affected muscles and then massage them. If the patient is in deep water when the cramp occurs, he or she can float in prone position (called a jellyfish float or survival float) while stretching and massaging the affected muscles. Initially, the pain may worsen as the patient begins to stretch, but the pain should subside as the muscle relaxes. Massaging the area increases blood flow to the muscles that brings more oxygen and reduces lactic acid that may be a contributing factor.

Once you have released the cramp, give the affected muscles time to fully recover. If the patient has been very active on a warm day, the patient may benefit from sipping water or a sports drink.

cribbing

A temporary wooden structure used to support heavy objects during construction, vehicle extrication and urban search and rescue. It is commonly used to secure overturned motor vehicles, and debris within collapsed buildings. Cribbing is also known as a box crib.

The stability of a crib is affected by a variety of factors: the material used (often a soft wood which gives audible warnings before failure), the number of contact points between the crib and the supported surface, the ratio of the footprint of the crib to its height, and the area of contact made between the crib and the ground and supported surface.

Cribbing is usually accomplished with blocks of wood, often 4″x 4″ or 6″x 6″ and 18″-24″ long. Soft woods, like spruce and pine are often preferred because they crack slowly and make loud noises before completely failing, whereas stiffer woods may fail explosively and without warning.

Cribbing may also be made out of plastic, which unlike wood is not susceptible to rot or corrosion from fluids the cribbing may come in contact with (e.g. oil, gasoline, hydraulic fluid).

Cribbing equipment is normally of three varieties: rectangular blocks, wedges (also called shims), and “step chocks” (large wooden chocks constructed of wood of different lengths). Blocks are the bread and butter of cribbing and are used in most cribbing evolutions.

critical incident stress

Stress triggered by involvement in a serious or traumatic event.

critical incident stress debriefing (CISD)

An adaptive, short-term psychological helping-process that focuses solely on an immediate and identifiable problem. It can include pre-incident preparedness to acute crisis management to post-crisis follow-up. Its purpose is to enable people to return to their daily routine more quickly and with less likelihood of experiencing post-traumatic stress disorder (PTSD). Evidence-based reviews, however, have concluded that CISD is ineffective, and sometimes harmful, in treating PTSD, depression, anxiety, and general psychological morbidity, and should not be used. 

• In fact, a number of studies have shown that CISD has little effect, or that it actually worsens the trauma symptoms. Several meta-analyses in medical literature either find no preventative benefit of CISD, or a negative impact for those debriefed. 
• On the other hand, Jacobs, Horne-Moyer and Jones argue that CISD has beneficial effects when conducted with emergency services personnel, although it does not work, or does more harm than good, with accident victims.

critical injury

Trauma to a patient that:

• Is life-threatening
• Produces unconsciousness
• Results in a substantial loss of blood
• Involves the fracture of an arm or leg
• Involves the amputation of a body part
• Consists of burning, freezing, or destructive force that involve a major portion of the body, that affect breathing, or that damage the face, a hand, a foot, or the genitals
• Causes loss of sight in one or both eyes

critical parts

The machinery, equipment, materials, structures, or other areas that are more likely than other components to result in a major problem or loss when worn, damaged, abused, misused, or improperly applied.

cross bearing

A technique for determining the location of a submerged victim at a beach or waterfront, performed by two lifeguards or bystanders some distance apart on the shore, each taking a sighting that cross at the position the victim was last seen.

croup

A common upper respiratory problem in young children characterized by breathing difficulty and a harsh, barking cough. Croup is also known as laryngotracheobronchitis.

Croup usually occurs a few days after the start of a cold and is often caused by the same viruses that cause the common cold. Croup is contagious, passing from one person to another through coughing, sneezing and close contact. Regular hand-washing and limiting contact with others can help prevent the spread of croup.

As children grow older and their lungs and windpipes mature, they are less likely to get croup. Getting a flu vaccine each year may help your child fight off some of the viruses that can lead to croup.

To care for croup:

• Keep your child calm even though he or she might be scared. Crying can cause the airway to swell even more, making breathing difficulty worse.
• Create a steam with a hot shower and have your child breath the moist air for 10 to 15 minutes. Do not put your child in the shower.
• Breathing cool night air also helps sometimes. Dress your child warmly and go outside for about 10 minutes.
• Keep the child well hydrated. Give water, flavored ice pops, or other crushed-ice drinks several times each hour.
• Keep your child away from cigarette smoke.
• Do not give your child cough medicine or cold medicine.

If the child symptoms are not relieved, contact your child’s doctor. If the child is have severe breathing difficulties, call 911 or the local emergency number.

cryptosporidiosis

An infection caused by the cryptosporidium parasite.

cryptosporidium

Cryptosporidium infection (cryptosporidiosis) is a recreational water illness (RWI) caused by tiny cryptosporidium parasites. When cryptosporidia enter your body, they travel to your small intestine and burrow into the walls of your intestines. Later, they are shed in your feces.

In most healthy people, a cryptosporidium infection produces watery diarrhea and flu-like symptoms that go away within a week or two. If you have a compromised immune system, a cryptosporidium infection can become life-threatening without proper treatment.

You can help prevent a cryptosporidium infection by practicing good hygiene and avoiding swallowing water from pools, recreational water parks, and natural bodies of water.

Cryptosporidium parasites are one of the most common causes of diarrhea in humans. This parasite is difficult to eradicate because it’s resistant to many chlorine-based disinfectants and can’t be effectively removed by many filters. Cryptosporidia can also survive in the environment for many months at varying temperatures, though the parasite can be destroyed by freezing or boiling.

To learn more about cryptosporidium, go to the CDC Cryptosporidium page.

CT inactivation value

See concentration-time inactivation value.

cyanosis

A bluish discoloration of the skin or mucous membranes caused by lack of oxygen in the blood. Its root is a Greek word for “blue.” Cyanosis is caused when much of the blood circulating through the body is “blue,” or oxygen-poor, rather than “red,” or oxygen-rich.

cytoplasm

The region of the cell within the membrane that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus.

D

daily log

A written journal of daily activities, statistical data, and important happenings kept by the aquatic staff.

DAN

Diver’s Alert Network.

DBP

Disinfection by-product.

deafness

The loss of hearing in one or both ears. Deafness can be mild, moderate, severe, or profound. It can occur at birth or be acquired later in life due to illness, noise exposure, injury, etc.

deceased/nonsalvageable/expectant (black)

A triage category for those involved in a multicasuality incident (MCI) indicating that the tagged patient is obviously dead or has sustained nonlife-sustained injuries.

decompression sickness

A sometimes fatal disorder caused by the release of gas bubbles (e.g., nitrogen) in body tissue due to a rapid decrease in air pressure after a stay in a compressed atmosphere. Decompression sickness is marked by neuralgic pains and paralysis, distressed breathing, and collapse. Also called the bends.

deep

Away from the surface of the body; internal.

deep water

(1) Water over the swimmer’s head when standing on the bottom. (2) Water deeper than 5 feet (1.5 m). (3) When used as the phrase “in deep water,” in trouble or in a difficult or dangerous situation.

deep-water line search

A search pattern for deep, murky water in which several lifeguards with mask and fins surface dive in a line formation and swim underwater about four body lengths to cover sections of waterfront to find a submerged victim. To avoid missing any of the search area, the lifeguards line up after resurfacing from each dive at the position of the lifeguard furthest back and then the line backs up another body length before surface diving to continue the search. A group leader usually takes a position at one end of the line to direct this process and to initiate each surface dive.

defibrillation

An electric shock administered by an automated external defibrillator (AED) to correct a life-threatening abnormal heart rhythm.

dehydration

An abnormal depletion of body fluids. To prevent dehydration, drink plenty of water before, during, and after you are active or in the sun. Do not wait until you feel thirsty to begin drinking. Avoid alcoholic beverages when you need to hydrate. Consider a sports drink or milk if you are working in the sun for more than one hour.

delayed care (yellow)

A triage category for those involved in an multicasuality incident (MCI), indicating that care can be delayed for the tagged patient without endangering that patient’s survival.

delayed drowning

A life-threatening condition in which a person who, after apparently recovering from respiratory impairment in the water due to drowning, suffers complications in the form of acute respiratory distress syndrome or similar trauma to the lungs that affects the amount of oxygen entering the bloodstream. A person experiencing this condition have have headaches, chest pain, breathing difficulty, lethargy, irritability, and/or lack of bowel or bladder control. The person may cough up a white or pinkish frothy liquid.

All drowning victims who have been unconscious, who have swallowed water, who have had a seizure in the water, or who experience any of the signs and symptoms of delayed drowning should go to the hospital emergency room despite the fact that they appear to be fully recovered. The effects of delayed drowning may not manifest until hours after the drowning incident.

The American Lung Association has information about ARDS. Although ARDS more often occurs with individuals who are critically ill and in the hospital already, it related to first aid and lifeguarding because it can occur with any patient who aspirates water or their own vomit.

To read a few recent cases of delayed drowning (sometimes called “secondary drowning” or erroneously “dry drowning”), click the links below:

• Liberty High School (Bethlehem PA) teacher and district not held responsible for delayed drowning victim; mother seeks US Supreme Court appeal. This incident occurred in 2010.
• Tragic death of a 10-year-old about one hour after swimming in a pool and having a submersion incident. This incident occurred in 2008.
• Toddler Nearly Drowns Hours After Leaving Pool (WFSB.com Kansas City, MO). This was reported in 2014.

Additional articles of interest about delayed or secondary drowning (sometimes called “dry” drowning):

• Dry Drowning (Snopes.com), 2015
• Dry Drowning and Secondary Drowning (WebMD)
• Inhaling water can have a delayed and dangerous reaction in kids (Heart of America Medical Center), 2015
• Learn the Facts About Drowning (NJTVonline.org), 2014
• Secondary Drowning: Shawnee Mission Health Update, 2014
• What You Need to Know About Dry Drowning (Parenting.com)

Although the term delayed drowning has been discouraged by the new definition of drowning, established in 2002 at the World Congress on Drowning (as reported by WHO), there is still a need for this term and others in educational and news reporting settings. Here is an open email sent by Water Safety Guy to the WCD: Follow-up of 2002 Definition of Drowning.

dementia

A general term for a decline in mental ability severe enough to interfere with daily life. Memory loss is an example.

Dementia is not a specific disease. It’s an overall term that describes a wide range of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person’s ability to perform everyday activities. Alzheimer’s disease accounts for 60% to 80% of cases. Vascular dementia, which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.

Dementia is often incorrectly referred to as “senility,” which reflects the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.

dermatitis

An inflammation of the skin resulting from a variety of different causes. Signs and symptoms of dermatitis may include: 

• Red rash, bumps or a burn-like rash on the skin
• Itchy, painful or burning skin
• Blisters and draining fluid

Two common types of dermatitis include atopic dermatitis (eczema) and contact dermatitis.

diabetes

Diabetes is a condition that causes blood sugar to rise to dangerous levels. There are two main types of diabetes: type 1 and type 2. Both may be inherited, so a family history of diabetes can significantly increase a person’s risk of developing the condition. If left untreated, diabetes can lead to blindness, kidney disease, nerve damage, heart disease and stroke.

diaphragm

A dome-shaped, muscular partition separating the chest from the abdomen. The diaphragm plays a major role in breathing, as its contraction increases the volume of the chest, thereby helping to inflate the lungs.

diastolic blood pressure

The lowest blood pressure in the arteries. The lowest blood pressure occurs when the heart muscle relaxes between beats. In a typical blood pressure reading, such as 120/78, the lower number is diastolic blood pressure and is measured in millimeters of mercury (mmHg).

diet

The foods that a person eats and drinks. Diet plays a major role in lowering your risk for heart disease and stroke. To keep your heart healthy and avoid those risks, the American Heart Association recommends a balanced diet low in added sugars, sodium and cholesterol.

digestive system

A body system composed of organs of gastrointestinal tract and accessory organs such as the salivary glands, liver, gallbladder, and pancreas. The digestive system is responsible for the physical and chemical breakdown of food, the absorption of nutrients, and the elimination of solid wastes.

direct contact

A mode of disease transmission that occurs through directly touching infected blood or body fluids.

direct pressure

A technique for controlling severe bleeding by pressing firmly on the wound, usually with a gloved hand after applying a sterile dressing or clean cloth. Direct pressure can be applied to wounds on all parts of the body except for the following:

• A scalp wound when a skull fracture is suspected.
• A wound to the eyeball.
• A wound with an impaled object.
• Any wound with exposed bones or organs.

In some cases, pressure can be applied to the area around these wounds to lessen bleeding. In other cases, hemostatic agents can be applied.

disability

A physical, sensory, intellectual, psychological variation intrinsic to an individual that results in an impairment or limitation. In the medical model of disability, the impairment itself is seen as reducing the quality of life and causing clear disadvantages to the individual. In the social model of disability, the emphasis is on the systemic barriers, negative attitudes, and exclusion by society as the true source of the individual’s disadvantage. To see how one company reflects the social model of disability, check out the Toys R Us toy guide for “differently abled” children.

disease

An abnormal condition that prevents the body or mind from functioning properly, resulting from various causes, such as infection, inflammation, environmental factors, or genetic defect and characterized by an identifiable group of signs and symptoms.

disease-causing agent

A pathogen (i.e., bacteria, viruses, etc.) capable of causing infection or illness.

disinfection by-products (DBPs)

A class of compounds generated in water that is disinfected with chlorine or other halogen (e.g., iodine or bromine). The disinfectant reacts with the organic material in the water and generates hundreds of different compounds. Some of these are toxic, some can cause birth defects, some are genotoxic, which damage DNA, and some we know are also carcinogenic. These include trihalomethanes (THMs), haloacetic acids (HAAs), chlorite, and so-called “emerging” DBPs such as halonitromethanes, haloacetonitriles, haloamides, halofuranones, iodo-acids such as iodoacetic acid, iodo-THMs (iodotrihalomethanes), nitrosamines, and others.

DBPs can be present in drinking water and swimming pools and hot tubs. The disinfectant in the water reacts with organic material brought into the water by people who use the pool or hot tub. They sweat; introduce lotions, sunscreens, and cosmetics; and urinate in the water. Hair and skin falls off into the water and chemicals applied to the locker room floors and decks are tracked into the pool. Because the water is recycled again and again, the levels of DBPs can be many times higher than in drinking water.

Epidemiological studies have looked at the associations between exposure to DBPs in drinking water with cancers, adverse birth outcomes, and birth defects. Meta-analyses and pooled analyses of these studies have demonstrated consistent associations for bladder cancer and for babies being born small for gestational age, but not for birth defects. Early-term miscarriages have also been reported in some studies. The exact putative agent remains unknown, however, in the epidemiological studies since the number of DBPs in a water sample are high and exposure surrogates such as monitoring data of a specific by-product (often total trihalomethanes) are used in lieu of more detailed exposure assessment. The World Health Organization has stated that “the risk of death from pathogens is at least 100 to 1,000 times greater than the risk of cancer from disinfection by-products (DBPs)” {and} the “risk of illness from pathogens is at least 10,000 to 1 million times greater than the risk of cancer from DBPs.”

distance per stroke (dps)

A measure of stroke speed and efficiency, the yards or meters traveled during one complete cycle of the arms. Also called stroke length.

distributive shock

Any type of medical shock caused by inadequate distribution of blood in blood vessels or throughout the body which results in decreased blood volume returning to the heart. Distributive forms of shock include anaphylaxis, neurogenic shock, septic shock, and vasogenic shock.

Diver’s Alert Network (DAN)

The diving industry’s largest association dedicated to scuba diving safety. Serving scuba divers for more than 30 years, DAN provides emergency assistance, medical information resources, educational opportunities, and more. 

DAN is supported by membership dues and dive accident insurance. Through its nonprofit efforts DAN first recognized the need for scuba divers to have insurance to help cover the cost of treatment for scuba diving injuries. DAN fulfilled that need by developing diving’s first dive accident insurance program, still the industry leader 25 years later. DAN Members enjoy great benefits, including TravelAssist, Alert Diver magazine, WorldCue® Planner and access to industry-leading insurance products.

One of DAN’s best-known resources is the 24-hour DAN Emergency Hotline (+1-919-684-9111), which stands ready every hour of the day to help scuba divers in need.

To learn more about DAN, go to the Diver’s Alert Network website.

diving

A head-first entry from a deck, dock, or diving board into the water.

diving board

An apparatus used for entering deep water that consists of a springboard mounted to a 1- or 3-meter structure with an adjustable fulcrum to increase or decrease the bounce in the board.

diving platform

An elevated stationary structure used for diving. Often, diving platforms are built into a diving tower with diving boards and platforms are various heights.

diving tower

An elevated structure used for diving that consists of diving boards and platforms of various heights: 1, 3, 5, 7.5, and 10 meters.

diving well

A deep pool usually separated from the main pool and designated for springboard diving.

diving well bubbler system

A mechanism that creates a cushion of aerated water on the surface of the pool, allowing springboard and platform divers to practice new dives while reducing the risk of severe injury as a result of a poor landing. Also known as an air sparging system.

dolphin kick

A leg kick performed with the butterfly stroke by thrusting legs downward together in a “fishtail” action from the hip and recovering the legs upward, timed to the wave-like movement of the entire body, thus producing one or two kicks per arm cycle.

do no harm

A principle in first aid and medical care that those who help others should do their best not to cause further injury to the patient.

do not resuscitate (DNR) order

An advance directive that spells out a patient’s wishes not to receive CPR, rescue breathing, or other resuscitative efforts. Usually a DNR order is used with terminal patients in a hospital or convalescent home or under hospice care.

Down syndrome

The most common genetic condition (occurring in 1 of every 691 babies) most often caused by an extra 21st chromosome. This extra genetic material alters the course of development and causes characteristics associated with the condition, such as cognitive delays, low muscle tone, small stature, an upward slant of the eyes, and a single deep crease across the middle of the palm. Every person with this condition is a individual and may possess these characteristics to varying degrees or not at all. Children with Down syndrome learn to sit, walk, talk, play, and do most other activities. only somewhat later than their peers without Down syndrome. About 10% to 20% of children with Down Syndrome have atlantoaxial instability (a looseness in the ligaments supporting the cervical vertebrae) and should not learn head-first diving.

To learn more about Down syndrome, go to What is Down syndrome? (NDSS).

drain

A fixture that provides an exit-point and conduit for waste water, rain water, or water that is to be recirculated.

At swimming pools, separate drainage systems are used in locker rooms, the deck, swimming pool overflow gutters, and the bottom of the pool to recirculate pool water and also remove waste water to the sewer.

A swimming pool should be closed if the water is too cloudy or murky to see the main drain (located at the deepest part of the pool) from the deck.

droplet transmission

A mode of disease transmission that occurs when a person inhales droplets of saliva or other body fluids from an infected person’s cough or sneeze; also known as respiratory droplet transmission.

drowning

Respiratory impairment from being immersed or submerged in a liquid. Drowning is further classified by outcome: death, ongoing health problems, and no ongoing health problems. For more information about the origin of this definition, go to the WHO Bulletin that explains it in several languages.

The illustration on the right by the Great Lakes Surf Rescue Project gives the common signs of an active drowning victim. Collectively, these signs have been described (by Frank Pia, PhD) as the instinctive drowning response. This struggle at the surface is usually silent and brief (20 to 60 seconds or less).

When the human body is submersed, there is an unconscious drive to breath-hold. Breath-holding occurs when the victim closes the larynx to prevent air from being inhaled or exhaled. Once submersed, the victim will quickly deplete oxygen stores. As the drowning process continues, the victim becomes progressively acidotic, hypoxic, and hypercapnic. Hypercapnia is the primary stimulus of the respiratory drive. If the victim hyperventilates prior to the incident, there may be a loss of consciousness from cerebral hypoxia prior to feeling the hypercapnic drive to breathe, a phenomenon referred to as “hypoxic blackout” or “shallow water blackout.” This phenomenon is sometimes seen in swimming competitions and in military training. Without hyperventilation, the victim will swallow water due to involuntary inspiration caused by the hypercapnic respiratory drive. The presence of water in the airway may cause laryngospasm, and no initial aspiration of water will occur (although water can be ingested at this point). Eventually the laryngospasm relaxes, likely due to both cerebral hypoxia and tissue fatigue, and the victim usually aspirates.

The amount of fluid ingested during the drowning process varies among victims, but ingestion of water is thought to be the main contributing factor to the vomiting seen in the majority of drowning victims.

dry chlorine

A granular form of chlorine added to swimming pools, such as calcium hypochlorite, chlorinated cyanurates, and lithium hypochlorite.

dry drowning

A condition in which a drowning victim’s larynx spasms (laryngospasm), preventing water from being aspirated into the lungs. In 80% to 90% of drowning victims, the laryngospasm relaxes so the victim’s final gasps for air cause water to enter the lungs. This has sometimes been referred to as a wet drowning. In 10% to 20% of cases, the laryngospasm remains in place until the victim stops breathing. Since fluids cannot flow passively into the lungs, the lungs are relatively “dry” even though the victim is often submerged.

The terms wet and dry drowning are somewhat misleading, and dry drowning has been used as a synonym for delayed or secondary drowning, which is a very different condition. In 2002, the World Congress on Drowning developed a new definition for drowning in an effort to eliminate the use of these terms. For more information, refer to the WHO Bulletin describing the decision made by this body.

dry-land training

The use of out-of-water techniques (e.g., stretching, resistance workouts, weight training, etc.) to improve swimming skills.

DuoDote™

A brand name for an auto-injector unit that contains premeasured doses of the drugs atropine and pralidoxime, which are used to counteract the effects of poisons and nerve agents on the body.

durable power of attorney for health care

A legal form that allows an individual to empower another with decisions regarding his or her healthcare and medical treatment. Healthcare power of attorney becomes active when a person is unable to make decisions or consciously communicate intentions regarding treatments.

duty

An act or a course of action that is required of one by position, social custom, law, or religion.

duty to act

A legal obligation to take necessary action to prevent harm to another person or to the public. In personal injury law, an individual may be held to a reasonable standard of care to prevent injury or harm.

dyspnea

Difficult or labored breathing; shortness of breath. Dyspnea is a sign of serious disease of the airway, lungs, or heart. The onset of dyspnea should not be ignored; it is reason to seek medical attention.