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

S

Safe Swim Defense

A training program and defensive strategy developed in the 2000 by Rich Diesslin, a cartoonist and former BSA lifeguard, and adopted by the Boy Scouts of America (BSA) to act as a safety standard for all in-water aquatic activities, including “backyard, hotel, apartment, and public pools; at established waterfront swim areas such as beaches at state parks and U.S. Army Corps of Engineers lakes; and at all temporary swimming areas such as a lake, river, or ocean.” The Safe Swim Defense applies to swimming and other nonswimming activities whenever participants enter water over knee deep or when submersion is likely. This means that the Safe Swimming Defense applies when BSA groups are fording a stream, seining for bait, or constructing a bridge over water as a pioneering project.

Important: Because of concerns with hyperventilation and hypoxic blackout, competitive underwater swimming events are not permitted in Scouting.

Certain activities require additional knowledge. For example, snorkeling in open water requires each participant to have demonstrated knowledge and skills equivalent to those for Snorkeling BSA in addition to the Safe Swim Defense. Scuba activities must be conducted in accordance with the BSA Scuba policy found in the Guide to Safe Scouting.

The Safe Swim Defense does not apply to boating activities and water sports such as water skiing. The safety standard for these activities can be found in the BSA Safety Afloat guidelines.

The Safe Swim Defense has 8 key points:

Qualified Supervision-All swimming activity must be supervised by a mature and conscientious adult age 21 or older who understands and knowingly accepts responsibility for the well-being and safety of those in his or her care, and who is trained in and committed to compliance with the eight points of BSA Safe Swim Defense.
Personal Health Review-A complete health history is required of all participants as evidence of fitness for swimming activities. Forms for minors must be signed by a parent or legal guardian.
Safe Area-All swimming areas must be carefully inspected and prepared for safety prior to each activity. Water depth, quality, temperature, movement, and clarity are important considerations. Hazards must be eliminated or isolated by conspicuous markings and discussed with participants.
Response Personnel (Lifeguards)-Every swimming activity must be closely and continuously monitored by a trained rescue team on the alert for and ready to respond during emergencies. Professionally trained lifeguards satisfy this need when provided by a regulated facility or tour operator. When lifeguards are not provided by others, the adult supervisor must assign at least two rescue personnel, with additional numbers to maintain a ratio of one rescuer to every 10 participants.
Lookout-The lookout continuously monitors the conduct of the swim, identifies any departures from Safe Swim Defense guidelines, alerts rescue personnel as needed, and monitors the weather and environment.
Ability Groups-All youth and adult participants are designated as swimmers, beginners, or nonswimmers based on swimming ability confirmed by standardized BSA swim classification tests. Each group is assigned a specific swimming area with depths consistent with those abilities.
Buddy System-Every participant is paired with another. Buddies stay together, monitor each other, and alert the safety team if either needs assistance or is missing. Buddies check into and out of the area together.
Discipline-Rules are effective only when followed. All participants should know, understand, and respect the rules and procedures for safe swimming provided by Safe Swim Defense guidelines.

Before any BSA group can participate in swimming or other activities in the water, at least one leader must be trained in the Safe Swimming Defense, have possession of the commitment card where the activity is taking place, and agree to all 8 key points.

The BSA website has more information about the Safe Swim Defense.

safety

The state of being protected against the consequences of physical harm. Also, the elimination or control of recognized and anticipated hazards to the degree that an acceptable level of risk is achieved.

Safety Afloat

A Boy Scouts of America (BSA) training program and safety standard used with all boating activities. Adult leaders supervising activities afloat must have completed Safety Afloat training within the previous two years. Cub Scout activities afloat are limited to council or district events that do not include moving water or float trips (expeditions).

Safety Afloat standards apply to the use of canoes, kayaks, rowboats, rafts, floating tubes, sailboats, motorboats (including waterskiing), and other small craft, but do not apply to transportation on large commercial vessels such as ferries and cruise ships. Parasailing (being towed airborne behind a boat using a parachute), kitesurfing (using a wakeboard towed by a kite), and recreational use of personal watercraft (small sit-on-top motorboats propelled by water jets) are not authorized BSA activities.

Safety Afloat guidelines consist of 9 key points:

Qualified Supervision-All activity afloat must be supervised by a mature and conscientious adult age 21 or older who understands and knowingly accepts responsibility for the wellbeing and safety of those in his or her care and who is trained in and committed to compliance with the nine points of BSA Safety Afloat. That supervisor must be skilled in the safe operation of the craft for the specific activity, knowledgeable in accident prevention, and prepared for emergency situations.
Personal Health Review-A complete health history is required of all participants as evidence of fitness for boating activities. Forms for minors must be signed by a parent or legal guardian.
Swimming Ability-Operation of any boat on a float trip is limited to youth and adults who have completed the BSA swimmer classification test.
Life Jackets-Properly fitted U.S. Coast Guard–approved life jackets must be worn by all persons engaged in boating activity (rowing, canoeing, sailing, boardsailing, motorboating, waterskiing, rafting, tubing, and kayaking). Type III life jackets are recommended for general recreational use.
Buddy System-All participants in an activity afloat are paired as buddies who are always aware of each other’s situation and prepared to sound an alarm and lend assistance immediately when needed. When several craft are used on a float trip, each boat on the water should have a “buddy boat.” All buddy pairs must be accounted for at regular intervals during the activity and checked off the water by the qualified supervisor at the conclusion of the activity. Buddies either ride in the same boat or stay near each other in single-person craft.
Skill Proficiency-Everyone in an activity afloat must have sufficient knowledge and skill to participate safely. Passengers should know how their movement affects boat stability and have a basic understanding of self-rescue. Boat operators must meet government requirements, be able to maintain control of their craft, know how changes in the environment influence that control, and undertake activities only that are within their personal and group capabilities.
Planning-Proper planning is necessary to ensure a safe, enjoyable exercise afloat. All plans should include a scheduled itinerary, notification of appropriate parties, communication arrangements, contingencies in case of foul weather or equipment failure, and emergency response options.
Equipment-All craft must be suitable for the activity, be seaworthy, and float if capsized. All craft and equipment must meet regulatory standards, be properly sized, and be in good repair. Spares, repair materials, and emergency gear must be carried as appropriate. Life jackets and paddles must be sized to the participants. Properly designed and fitted helmets must be worn when running rapids rated above Class II. Emergency equipment such as throw bags, signal devices, flashlights, heat sources, first-aid kits, radios, and maps must be ready for use. Spare equipment, repair materials, extra food and water, and dry clothes should be appropriate for the activity. All gear should be stowed to prevent loss and water damage. For float trips with multiple craft, the number of craft should be sufficient to carry the party if a boat is disabled, and critical supplies should be divided among the craft.
Discipline-Rules are effective only when followed. All participants should know, understand, and respect the rules and procedures for safe boating activities provided by Safety Afloat guidelines.

The BSA website has more information about Safety Afloat.

safety communication

The collective means by which safety information is disseminated to employees, including the classroom, departmental safety meetings and written communications such as posters, newsletters and postings of regulatory agency inspection findings.

safety coordinator

An individual within a department or college who assists in implementing the workplace safety program for the department, college, or area.

safety culture

The attitudes, motivations, and knowledge of a group that affect the extent to which safety is emphasized over competing goals in decisions and behavior. It is the way safety is perceived, valued, and prioritized within a group, reflecting the group’s real commitment to safety at all levels. It is how group members acts upon safety issues when they think no one is watching.

Safety culture cannot be purchased, dictated, or implemented through policy. It must develop from within an organization or group organically as a by-product of the group’s combined commitment and efforts to prize safety as a core value and key priority.

safety data sheet (SDS)

Literature prepared by a manufacturer that contains information such as a list of hazardous ingredients, safety precautions for handling, spill- or release-response procedures and first aid instructions. Formerly known as material safety data sheet (MSDS).

safety management system

A comprehensive business program designed to manage the safety elements in the workplace. It is an organization’s competence in the area of safety as reflected in its rules, regulations, policies, procedures, and work practices.

salt

A crystalline compound that has sodium. Many people eat too much salt, putting them at greater risk for cardiovascular diseases as they get older. Eating less salt can help lower your blood pressure or prevent it from developing in the first place.

1/4 teaspoon salt = 575 milligrams of sodium
1/2 teaspoon salt = 1,150 mg sodium
3/4 teaspoon salt = 1,725 mg sodium
1 teaspoon salt = 2,300 mg sodium

sand

Loose, granular material that results from the breakdown and grinding of rocks and consists of particles smaller than gravel but coarser than silt. Clean, processed sand is used as a medium for swimming pool filters.

sand filter

A large device containing sand (i.e., quartz, silica, or zeolites) through which swimming pool water is passed to remove suspended particles. As water flows from the top of the filter to the bottom, particles of dirt and other solids are trapped by the sand so that cleaner water flows from the base of the filter and back into the swimming pool.

scanning

The act of carefully and thoroughly surveying all or part of a swimming area using visual sweeps to detect hazards, dangerous activities, and distressed or drowning victims. Scanning is challenging work because it must be focused, continuous, and in-depth, requiring vigilance, situational awareness, a high level of attentiveness, and, when needed, a decisive sensorimotor response.

scissors kick

A kick for swimming performed on the side in which the legs move apart and then together again in a scissor-like action, top leg forward and bottom leg back; used primarily in the sidestroke and Trudgen strokes.

scull

(1) An oar over the stern of a boat (e.g., a gondola) moved from side to side to propel the boat forward. (2) Either of a pair of oars used together by a person or crew to propel a boat forward. (3) A boat that uses sculls for propulsion. (4) The side-to-side movement of a swimmer’s hand to move through the water without kicking or stroking or to stabilize position at the surface.

sculling

A sideways, in-and-out movement of the hands in water to create propulsion. The path your hands take is similar to figure-eights with thumbs up and pinkies down as your hands move in, and thumbs down and pinkies up as your hands move out.

Sculling also refers to a method of using oars to propel watercraft in which the oar or oars touch the water on both the port and starboard sides of the craft, or over the stern. By extension, the oars themselves are also often referred to as sculls when used in this manner, and the boat itself may be referred to as a scull.

To see videos on swimming sculls, click these links:

A Guide to Sculling (VideoJug)-Sculls shown are the back scull (head first) and the snail scull (feet first).
Training videos by Ymajahi Brooks for Expert Village (2008):

scum

A filmy layer of extraneous or impure matter the forms on the surface of the water or clings to the tiles or walls of a swimming pool.

secondary responsibilities of a lifeguard

Other duties a lifeguard must do, such as testing the pool water chemistry, assisting patrons, performing maintenance, completing records and reports, or performing opening duties, closing duties or facility safety checks. Secondary responsibilities should never interfere with a lifeguard’s primary responsibility.

seiche

A wave created by air pressure and wind in an enclosed or partially enclosed body of water. Seiches and seiche-related phenomena have been observed on lakes, reservoirs, swimming pools, bays, harbors, and seas. The Illinois State Geological Survey has published an informative article on large seiches in Lake Michigan. Here is another good article on seiches and how they are formed, found on the Cayuga Fisher website.

sensorimotor response

The process of receiving sensory input from the environment and using that information to devise an appropriate motor response to what is perceived. Lifeguards receive sensory information from the pool area during scanning through sensory systems (e.g., vision, hearing, smell, etc.), organize this information in mind by comparing it to known criteria for defining hazards conditions and practices and the behaviors of victims, and select an appropriate response (e.g., do nothing, give a verbal warning, make a swimming rescue, etc.).

septic shock

A type of medical shock that occurs when a bacterial infection has spread into the bloodstream. Toxins released into the bloodstream damage vital organs and body tissue, causing blood pressure to drop severely.

shallow-angle dive

A headfirst entry in which the body enters the water at about a 45° angle in a streamlined position.

shallow-water blackout

Loss of consciousness while underwater swimming in water less than 16 feet deep, often due to hyperventilation and prolonged submersion resulting in cerebral hypoxia. Also called hypoxic blackout. Click to read a joint statement on hypoxic blackout by the American Red Cross and the YMCA of the USA.

shepherd’s crook

A reaching pole with a large, blunt hook on the end to encircle a drowning victim.

shock

A life-threatening condition in which the circulatory system fails to deliver blood to all parts of the body, causing body organs to fail. Shock may result from trauma, heatstroke, blood loss, an allergic reaction, severe infection, poisoning, severe burns, or other causes. When a person is in shock, his or her organs aren’t getting enough blood or oxygen. If untreated, this can lead to permanent organ damage or even death.

Different types of shock include: anaphylactic shock, cardiogenic shock, hemorrhagic shock, hypovolemic shock, neurogenic/vasogenic shock, obstructive shock, respiratory shock, and septic shock.

Signs and symptoms of shock vary depending on circumstances and may include:

Cool, clammy skin
Pale or ashen skin
Rapid pulse
Rapid breathing
Nausea or vomiting
Enlarged pupils
Weakness or fatigue
Dizziness or fainting
Changes in mental status or behavior, such as anxiousness or agitation

To care for shock:

Call 911 or the local emergency number.
Monitor the patient and care for any life-threatening conditions first.
Stop all bleeding, bandage wounds, and compress/support all injuries. Lessen pain and make the patient comfortable. Loosen tight clothing.
Do not give the patient anything to eat or drink.
If patient is not having difficulty breathing and there are no injuries to legs, hips, back, head or neck, have the patient lie down and raise the feet about 8–12 inches (20–30 cm).
Maintain the patient’s normal body temperature (do not chill or overheat the patient).
Stay with the patient. Provide comfort and reassurance.

To learn more about shock, click these links:

Medical Shock (MedicineNet)
Shock (MedlinePlus)
Shock (Merck Consumer)
Shock (Merck Professional)

SIA

Snow immersion asphyxiation.

sickle-cell anemia

A genetic blood disorder in which the body produces crescent-shaped red blood cells. This abnormal shape makes it difficult for blood to flow through blood vessels and impairs the cells’ ability to efficiently carry oxygen to the body’s tissues and organs. Affected cells often stick to blood vessel walls, increasing the risk for blocked arteries to the brain that can cause stroke. Blockages in the coronary arteries of the heart can lead to heart attack. This disorder mainly affects African-Americans.

side effect

A reaction that results from a medication or therapy. For example, heart failure medications can cause side effects such as headaches, nausea, dizziness, kidney complications, and low blood pressure.

sidestroke

A resting stroke, and former lifesaving stroke, performed on the side with the lower ear in the water and the rest of the head and one shoulder out of the water. In the sidestroke, one arm leads (is extended in front of the body) and the other trails (is placed extended on the hip). The leading arm pulls toward the body with arm bent while the trailing arm recovers to a position in front of the chest with elbow bent and palm down. The swimmer’s two hands almost touch. The leading arm then recovers to its extended position in front of the body while the trailing arm pushes back to its position on the hip. In other words, while the leading arm is in its power phase, the trailing arm is in recovery, and vice versa. The arms offer some propulsion and stabilize the body in the side-lying position, but most of the propulsion in this stroke comes from the scissors kick which is timed to the trailing arm pull.

For the scissors kick, the ankles are drawn back to the swimmer’s bottom as the trailing arm recovers. The legs then separate, top leg extending forward like taking a big step up the stairs; the lower legs goes backwards. Both feet are flexed as the legs make a semicircle, catching the water with the feet and legs, and coming together extended with toes pointed as the trailing arm pulls. After the trailing arm stroke and kick, the swimmer glides.

The sidestroke is an old stroke which may have been developed in the 1800s as an alternative to the breaststroke. Although the sidestroke is swum with the trailing arm recovering underwater, a variant of the sidestroke was invented in which the trailing arm recovers out of the arm like a short front crawl arm recovery with the arm entering the water at about eye level. In 1895, J. H. Thayers of England, using this “overarm sidestroke,” set a record for the 100-yard swim with a time of 1:02.50.

By the 1930s, the sidestroke was adopted as a lifesaving stroke for swimming rescues. The lifesaver would place the victim of the hip and hold the victim across the chest with the trailing arm and swim sidestroke using the leading arm and scissors kick. To avoid kicking the victim, the scissors kick was inverted with the top leg going backwards and the bottom leg going forward. The sidestroke continued to be the main lifesaving stroke until 1995 when the American Red Cross introduced equipment-based rescues using the rescue tube and double-arm grip on the victim’s shoulder. (Equipment-based rescues were practiced by other lifesaving agencies before 1995, such as Jeff Ellis and Associates, NASCO, and the YMCA, but the adoption of these new rescues by the American Red Cross caused a fundamental change in the majority of swimming pool, waterpark, and waveless waterfront lifeguarding.) Because of the position of the lifeguard and the double-arm grip, the eggbeater kick began to be used for lifeguard rescues.

The sidestroke remains a leisure/resting stroke.

To see the sidestroke, click these links:

How to Swim Sidestroke (Chris Burton)
Sidestroke Video by MARSOC

sighting

A technique for noting where a submerged victim was last seen, performed by imagining a line to the opposite shore and estimating the victim’s position along that line.

signs and symptoms of a heart attack

The following are common heart attack signs and symptoms:

Discomfort in the chest (pressure, squeezing, fullness)
Discomfort in other upper-body areas (arms, back, neck, jaw, or stomach)
Shortness of breath
A cold sweat
Nausea
Light-headedness

For men and women, the most common heart attack symptom is chest pain or discomfort. But women are somewhat more likely than men to experience some of the other common symptoms, particularly shortness of breath, nausea, vomiting, and back or jaw pain. Call 9-1-1 or the local emergency number if you think you or someone else is having a heart attack.

For more information, check out the Heart Attack page of the American Heart Association.

sinoatrial node (or sinus node)

The heart’s natural pacemaker. Located in the right atrium, the sinoatrial initiates the heart’s electrical activity by stimulating muscle contraction so the heart can pump blood to the body.

sinus rhythm

The normal heart rate and rhythm of the heart, typically 60 to 100 beats per minute.

situational awareness

The perception of elements in the environment within a volume of time and space, the comprehension of their significance, and the anticipated status of these elements in the near future. Situational awareness requires:

Extracting information from the environment.
Integrating this information with relevant internal knowledge to analyze create the current situation.
Using this analysis to direct future perceptual exploration in a continual cycle.
Anticipating future events.

Six Sigma

A set of practices originally developed by Motorola to systematically improve the quality and safety of manufacturing processes by eliminating defects. To read more about Six Sigma, go to About Six Sigma by 6Sigma.us.

slide-in entry

A lifeguard entry used for crowded shallow areas, murky water with unknown bottom conditions, and situations where minimizing turbulence from an entry is desired. It is also known as the ease-in or slip-in entry.

To perform the slide-in entry:

Sit on the deck or dock at the water’s edge with the rescue tube strap over one shoulder and the rescue tube to one side.
Facing the water and using both hands, lower yourself into the water gently so you do not disturb the water or land on the bottom hard.
Grab the rescue tube and position it under your armpits to begin an approach to the victim. If you are trying to minimize turbulence, use a breaststroke approach.

slip-in entry

Another name for the ease-in or slide-in entry.

snail scull

A feet-first scull performed on the back with arms at the sides of the body and fingers pointed downward so the effect of sculling moves water toward the head. In A Guide to Sculling (VideoJug), an example of the snail scull is shown (second scull demonstrated).

snow drowning

A common term (and somewhat of a misnomer) for the process of respiratory impairment due to being engulfed in ice and snow after being trapped in a snowbound tree well, a deep unconsolidated snow drift, or a collapsing snow fort or similar homemade structure. Suffocation in snow is also known as snow immersion asphyxiation (SIA) or nonavalanche-related snow immersion death (NARSID).

snow immersion asphyxiation (SIA)

Suffocation due to being engulfed in snow; sometimes called snow drowning, snow immersion suffocation, or nonavalanche-related snow immersion death (NARSID). Most snow-related suffocations occur when skiers, snowboarders, or hikers fall into a tree well, especially headfirst. A tree well, also known as a “spruce trap,” is a void or area of loose snow around the trunk of a tree enveloped in deep snow.

Deep snow accidents also can occur when people fall into an area of deep unconsolidated snow and they become immobilized. Struggling in the snow can make things worse; either they sink further into the drift or they become encased in hardened snow as it solidifies around them (like concrete).

According to Christopher Van Tilburg in Non-avalanche-related snow immersion deaths: tree well and deep snow immersion asphyxiation (September 2010), “…The exact duration of burial to time of death and the cause of death are not precisely known but can be postulated from accident reports, experimental snow burial studies, and avalanche literature. In most cases, death probably occurs within 15 to 30 minutes from the time of burial. However, survival after prolonged burial in a tree well and deep snow is possible. The cause of death is asphyxiation, probably due to one of the mechanisms that produce asphyxia in avalanche burial victims: positional asphyxia, airway obstruction, or carbon dioxide displacement asphyxia. Prevention of snow immersion asphyxiation begins with skiers and snowboarders staying within the limits of their skills, using the proper tools for deep powder, staying in control at all times, and employing a buddy system….”

If sucked into a tree well or deep bank of snow, try to tuck, roll, and land upright (to avoid ending up head down in the snow). If possible, grab a tree branch and yell to others with you. If buried upside down, stay calm and create an air pocket, which may buy you some precious minutes of breathing time while waiting to be found.

If your partner or someone else has a tree well or deep snow immersion incident:

Don’t leave to get help – Stay with your partner!
Call for additional resources.
Evaluate scene safety for yourself.
IMMEDIATELY begin snow immersion rescue efforts.
- Go directly for the airway, and keep it clear, be careful not to knock more snow into the hole. Clear any snow from the air way and continue necessary first aid or extrication efforts
Do not try to pull victim out the way they fell in. Instead, determine where the head is and tunnel in from the side.

To learn more about snow immersion, check out these links:

NSAA Snow Immersion Suffocation Fact Sheet (National Ski Areas Association)
Snow Immersion Suffocation (Sugar Bowl)
Tree Well and Deep Snow Accident Prevention (Stevens Pass)
Tree Well and Snow Immersion Suffocation (Pacific Northwest Ski Areas Association)

sodium

A mineral that helps to regulate the body’s water balance, to maintain normal heart rhythm and to conduct nerve impulses that generate muscle contractions. Getting too much sodium from food and beverages contributes to high blood pressure in some people because it holds excess fluid in the body, creating an added burden on the heart. Processed food is the source for 77 percent of sodium in the diet for most Americans. Excess sodium can also increase your risk for stroke and heart failure. The American Heart Association recommends choosing and preparing foods with little or no salt. To lower blood pressure, aim to eat no more than 2,400 milligrams of sodium per day. Reducing daily intake to 1,500 mg is desirable because it can lower blood pressure even further. It is estimated that an average intake of 1,500 milligrams a day would reduce high blood pressure in America by about 25 percent and save more than $26 billion in annual healthcare costs.

spasm

A sudden, temporary or prolonged contraction of a muscle or artery.

specific gravity

The ratio of the weight of the object to the weight of the water it displaces.

SPF

Sun protection factor.

sphygmomanometer

An instrument for measuring blood pressure, typically consisting of an inflatable rubber cuff that is applied to the arm and connected to a column of mercury next to a graduated scale, enabling systolic (pumping) and diastolic (resting) blood pressure measurements by increasing and gradually releasing the pressure in the cuff.

spinal column

The axial skeleton consisting of an articulated series of 33 vertebrae which extend from the neck to the lower back to protect the spinal cord. Also called the backbone. Each vertebra is cushioned by spongy sections of cartilage called intervertebral disks.

spinal cord

A bundle of nerves extending from the base of the skull to the lower back and protected by the spinal column. Damage to the spinal cord can cause paralysis or death.

spinal motion restriction

The preferred term used to describe the practice of attempting to maintain the spine in anatomical alignment and minimize gross movement with or without the use of specific adjuncts such as collars. This term should replace the use of “spinal immobilization” since the spinal cannot be truly immobilized.

The 2015 American Heart Association and American Red Cross Guidelines for First Aid recommendation that first aid providers should not use cervical collars to provide spinal motion restriction and, when a spinal injury is suspected, they should limit care to instructing the patient to remain as still as possible until EMS personnel can arrive to provide further assistance.

Lifeguards should still use manual methods of spinal motion restriction to support a victim and a backboard to remove the victim from the water.

sprain

The stretching and tearing of ligaments and other tissue structures at a joint.

spruce trap

A void or area of loose snow around a tree trunk that can trap hikers, snow skiers, etc. who get too close. Also called a tree well. Anyone trapped in a spruce trap may suffocate in the snow (snow immersion asphyxia) or suffer hypothermia or severe frostbite.

If sucked into a spruce trap or deep bank of snow, try to tuck, roll, and land upright (to avoid ending up head down in the snow). If possible, grab a tree branch and yell to others with you or around you. If buried upside down, stay calm and create an air pocket, which may buy you some precious minutes of breathing time while waiting to be found.

stages of heart failure

A rating system to evaluate the development and progression of heart failure symptoms developed by the American Heart Association and American College of Cardiology in 2001. This rating system has four stages.

Stages A and B represent people who have not yet developed heart failure but are at high risk because of coronary artery disease, high blood pressure, diabetes, or other predisposing conditions.
Stage C includes patients with past or current symptoms of heart failure who have a condition called structural heart disease.
Stage D includes patients who have advanced heart failure that is difficult to manage with standard treatment.

standard of care

The minimal quality of care expected of an emergency care provider.

standard precautions

The minimum infection prevention practices that apply to all patient care, regardless of suspected or confirmed infection status of the patient, in any setting where healthcare is delivered. These practices are designed to protect first aid and medical care providers and prevent these providers from spreading infections among patients. They include:

Good hand hygiene.
Use of personal protective equipment (PPE).
Safe injection practices.
Safe handling of potentially contaminated equipment and surfaces in the patient environment.
Respiratory hygiene/cough etiquette.

Standard precautions were developed in 1996 from universal precautions and body-substance isolation, older protocols in practice since the 1980s. For more information about standard precaution practices, go to the CDC’s Guide to Infection Prevention for Outpatient Settings: Minimum Expectations for Safe Care.

starting block

A raised platform from which competitive swimmers begin a race.

stationary scull

A type of sculling that supports a swimmer in a stationary position at the surface of the water. Stationary sculls are used in treading water, synchronized swimming, and water polo.

sterile

Clean and free of living microorganisms.

stern

The back of a boat or ship.

stethoscope

An instrument for listening to sounds within the body.

stoma

An opening in the front of the neck through which a person whose larynx has been removed breathes.

strain

The stretching and tearing of muscles or tendons.

straight position

A diving position in which the torso is straight or arched slightly backward with the legs together and straight; there is no bend at the hips or knees.

strep infection

An infection caused by Streptococcus bacteria, usually occurs in the throat. In rare cases, it can cause damage to otherwise normal heart valves in children, resulting in heart failure.

stress

Stress is bodily or mental tension in response to physical, chemical, or emotional factors. The link between stress and heart disease is not clear. However, chronic stress can cause an increase in heart rate and blood pressure that may damage the artery walls.

stretcher

A flat, supported framework with handles used for transporting the sick or injured. At a minimum, a stretcher is a sheet of canvas stretched between two poles with four handles. Also called a litter.

stroke

An interruption of blood flow to the brain causing paralysis, slurred speech, and/or altered brain function. About 9 of every 10 strokes are caused by a blockage in a blood vessel that carries blood to the brain; this is known as an ischemic stroke. The other type of stroke is known as hemorrhagic, caused by a blood vessel bursting. Warning signs include sudden numbness or weakness of the face, arm, or leg (especially on one side); sudden confusion, trouble speaking or understanding; sudden trouble seeing in one or both eyes; sudden trouble walking; dizziness; loss of balance or coordination; and/or sudden, severe headache with no known cause.

Act FAST to check someone for stroke. Note the time and call 9-1-1 or the local emergency number if you think you or someone else is having a stroke.

For more information, check out the National Stroke Association, the American Stroke Association, the Centers for Disease Control and Prevention, and the World Health Organization.

stye (also sty)

A bacterial infection at the root of an eye lash that causes a tender red lump on the eyelid. It is also called a hordeolum. Most styes occur along the edge of the eyelid. When a stye occurs inside the eyelid, it is called an internal hordeolum. Although a stye may be painful and annoying, it is rarely serious. Most go away on their own without treatment.

A stye usually starts as a red bump that looks like a pimple along the edge of the eyelid.

As the stye grows, the eyelid becomes swollen and painful, and the eye may water.
Most styes swell for about 3 days before they break open and drain.
Styes usually heal in about a week.

To care for a stye:

Apply warm, wet compresses for about 10 minutes 3 to 6 times per day.
Use an over-the-counter medication or eye wash.
Do not squeeze or lance a stye. (It is never a good idea to point sharp, piercing objects in the direction of your eyes!)
Do not wear eye makeup or contact lenses while your eyelid is infected.

To learn more about styes and related conditions, follow these links:

Chalazion and Stye (Merck)
7 Things to Know About Eye Styes (AllAboutVision)
Sty (Mayo Clinic)

submerged spinal victim

A drowning victim who has suffered a possible spinal injury due to a diving board injury, a surfing injury, a fall from a height, etc. and has slipped under the surface of the water. Most submerged victims do not have spinal injuries, but a spinal injury should be suspected if a sudden or severe injury directly caused unconsciousness and submersion.

A head, neck, or spinal injury complicates the rescue procedure, but, if the victim is unconscious and not breathing, giving rescue breaths or CPR as applicable has a higher priority than placing the victim on a backboard.

submerged spinal victim rescue

An underwater rescue in the American Red Cross and American Lifeguard Association Lifeguarding courses in which the lifeguard removes the rescue tube, submerges to the suspected spinal victim, secures the victim’s head and neck using the head splint or similar support, returns to the surface and positions the victim on the back with head and neck immobilized throughout the operation. Once at the surface with the victim, the lifeguard moves to shallow water and awaits the backboard.

If a second lifeguard is available, the second lifeguard can reinsert the first lifeguard’s rescue tube under the first lifeguard’s armpits.

If the victim is unconscious, not breathing, and without a pulse, the victim should be removed from the water as soon as possible so that CPR can be started.

Submerged Spinal Victim Rescue (American Lifeguard Association)-2nd skill demonstrated. This video also shows the submerged victim rescue (first skill), a different skill when a spinal injury is not suspected.

submerged victim

A drowning victim, either active or passive, that has slipped below the surface of the water.

Submerged deep water victim drill (courtesy DeAnza College)

submerged victim rescue

An equipment-based rescue in the American Red Cross and American Lifeguard Association Lifeguarding courses performed by surface-diving to the rear of a submerged, nonspinal victim while wearing or holding the shoulder strap of the rescue tube, using one arm to grasp the victim across the chest, and using the other arm to pull on the rescue tube towline to return to the surface with the victim. Once at the surface with the victim, the lifeguard retrieves the rescue tube and inserts it behind the victim and under his/her armpits. The lifeguard grasps the victim’s shoulders and tows the victim to safety.

Submerged Victim Rescue Drill (Swim Concierge Lifeguards). This is a Final Skill Scenario so it also includes removal from the water using two rescuers and the backboard and CPR. This Scenario is timed-2 minutes to rescue and remove the victim and 3 minutes of CPR.
Submerged Victim Rescue (American Lifeguard Association). This video also includes submerged spinal rescue, a different skill.

suctioning

The process of removing foreign matter from the upper airway by means of manual or mechanical device.

sudden cardiac arrest

A malfunction of the heart’s electrical system, causing the heart to suddenly stops beating, often without warning. While the terms “sudden cardiac arrest” and “heart attack” are often used as if they are synonyms, they aren’t. Sudden cardiac arrest can occur after a heart attack, or during recovery. Heart attacks increase the risk for sudden cardiac arrest, but most heart attacks do not lead to sudden cardiac arrest. Immediate CPR can double or triple the chances of survival from sudden cardiac arrest.

sugar and sugar intake

A sweet crystalline or powdered substance, white when pure, consisting of sucrose obtained mainly from sugarcane and sugar beets and used in many foods, drinks, and medicines to improve their taste. Also called table sugar. Naturally occurring sugars are better nutritionally than table sugar; these can be found in foods such as fruit (fructose) and milk (lactose).

The American Heart Association recommends no more than half of your daily discretionary calorie allowance come from added sugars. (Your daily discretionary calorie allowance consists of calories available after meeting nutrient needs.) This is no more than 100 calories per day for most American women and no more than 150 per day for men (or about 6 teaspoons a day for women and 9 teaspoons a day for men).

sun protection factor (SPF)

A measure of a sunscreen’s ability to prevent UVB from damaging the skin. Here’s how it works: If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer – about five hours. Most sunscreens with an SPF of 15 or higher do an adequate job of protecting against UVB. For more information, go to the Skin Cancer Foundation.

sunscreen

A cream, lotion, or spray that combines several ingredients that help prevent the sun’s ultraviolet (UV) radiation from reaching the skin. Two types of ultraviolet radiation,UVA and UVB, damage the skin and increase your risk of skin cancer. Sunscreens vary in their ability to protect against UVA and UVB. Most sunscreens with a sun protection factor (SPF) of 15 or higher do an adequate job of protecting against UVB.

To learn more about sunscreen, check out the Skin Cancer Foundation.

superficial burn

A burn involving only the epidermis, characterized by dry, red, tender skin. Also called a first-degree burn.

superior vena cava

A major vein that carries blood from the upper body to the heart.

support carry

A rescue move used in the military, performed by standing next to the victim, placing the victim’s arm over your shoulder and holding the wrist while supporting the victim’s waist with your other hand. Also known as the supporting assist or walking assist.

supporting assist

A rescue move or removal from the water at a sloping beach of a weak but standing victim, performed by standing next to the victim, placing the victim’s arm over your shoulder and holding the wrist while supporting the victim’s waist with your other hand. Also known as the support carry or walking assist.

surveillance

The act of carefully watching someone or something, like a lifeguard watching the public in the water or a police officer watching a building to detect or prevent a crime. Lifeguards use a technique called scanning to provide continuous surveillance of a swimming area.

survival float

A facedown float performed in warm water to conserve energy and await a rescue. To survival float, rest in a facedown position with face in the water and arms and legs slightly spread out and supported by the water. To breathe, exhale in the water and then press arms downward, bring legs together in a scissors kick and lift the head to inhale. After breathing, return to the resting position. See also survival stroke.

survival stroke

A stroke performed like the survival float except that arm stroke and kick performed with every breath is used to move in a forward direction toward safety.

swash

A turbulent layer of water that washes up on the beach after an incoming wave has broken. The swash action is followed by backwash, the receding movement of the water from the shore back to the ocean. Swash and backwash can move beach materials up and down the beach, which results in the cross-shore sediment exchange. The time-scale of swash motion varies from seconds to minutes depending on the type of beach. Greater swash generally occurs on flatter beaches.

swimming lessons

The formal process of learning to swim, usually within a program divided into levels, sections, or classes, each with a set of skills and performance criteria leading to some type of award or certificate upon successful completion of the minimum requirements.

swimming stroke

Any of the various styles of moving through the water using coordinated, circular or semicircular arm strokes, leg kicks, and rhythmic breathing. An exhaustive list of swimming strokes, styles, and variants follows:

Basic Strokes (taught in swimming lessons)
- Beginner stroke (also called human stroke)
- Combined stroke on back
- Combined stroke on front
- Dog paddle
- Survival stroke
- Underwater swimming
Back Strokes
- Back crawl
- Back double Trudgen
- Double-arm backstroke
- Elementary backstroke
- Inverted breaststroke
- Inverted butterfly
Competitive Strokes
- Backstroke
- Breaststroke
- Butterfly
- Freestyle
Front Crawl Strokes
- American crawl
- Australian crawl
- Catch-up crawl
- Corkscrew stroke
- Dolphin crawl
- Front crawl
- Head-high crawl
- Waltz crawl
Sculling strokes
- Alligator scull
- Back scull (also called head-first sculling)
- Canoe scull
- Dolphin scull
- Snail scull
- Support scull
- Torpedo scull
Side Strokes
- Combat sidestroke
- Lifesaving stroke
- Overarm sidestroke
- Sidestroke
Trudgen Strokes
- Double Trudgen
- Double Trudgen crawl
- Trudgen
- Trudgen crawl

synchronized diving

synchrodiving 1 — World-class synchronized diving

A competitive diving event involving two-diver teams that dive simultaneously and in an identical manner. Synchronized diving ha been an Olympic sport since 2000. Once it was possible to dive opposites, also known as a pinwheel, but this is no longer part of competitive synchronized diving. For example, one diver would perform a forward dive and the other an inward dive in the same position, or one would do a reverse and the other a back movement.

In synchronized diving, the diving is judged both on the quality of execution and the synchronicity – in timing of take-off and entry, height and forward travel.

To view synchronized diving efforts, check out the following links:

synchronized swimming

A sport (also called “synchro”) in which a team of swimmers perform coordinated movements in the water in time to music. Routines last from 2 to 5 minutes and comprise both above and underwater sections; the above water sections are called arms and consist of actual arm and leg movements done while the head is out of the water or the swimmer is lying across the surface of the water. Underwater sections are called figures or highlights.

Figures are the movements made with the legs above the water while the body is upside down in the water.
Highlights are special stunts that attract the attention of the audience, such as boosts (a swimmer is launched into the air) or lifts.

One of the American founding fathers, Benjamin Franklin, was actually a pioneer for synchronized swimming and is thought to have possibly invented it. Franklin was a good swimmer and an early proponent of the health benefits of the sport. During his travels to London in 1724, he would swim in the Thames River and perform maneuvers he called “ornamental swimming” for spectators.

Although synchro began as a male-dominated sport, the beauty and elegance required made the sport a natural for women who had less body weight and more buoyancy and grace for the technical and artistic aspects and also generally looked better during performances. Early performances in the late 1800s were called “water ballet” and were considered more of a dance performance than a sport.

Modern synchronized swimming was invented by Annette Kellerman, an Australian-born actor and swimmer who was a champion in distance swimming, and diving. She was also a practiced ballerina throughout the early 1900’s and caused quite an uproar in the media when she went to a beach in Boston, Massachusetts, wearing a one-piece swimsuit with bare arms and legs! Again in 1907 Kellerman caused more uproar in her fabulous one-piece swimsuit by performing underwater in a large glass tank at the New York Hippodrome. Her performances added to the rising popularity of synchro and raised lots of awareness for the sport.

Another person who was instrumental in the development of synchro was Katherine (“Kay”) Whitney Curtis, who performed at the 1934 Chicago’s World Fair. To Kay Curtis, synchronized swimming was a co-ed sport as it still might be if she hadn’t been transferred overseas (1943-1962) with the Red Cross as recreational director. She staged a production for the Armed Forces in the spectacular fountains and pools and gardens of the palace built by the Kings of the Two Sicilys in Caserta, Italy, which was being used as Allied headquarters. When she finally returned home in 1962 after observing synchronized swimming all over Europe, her baby was a full-blown sport and has been a dominant American aquatic sport and art form ever since. Her pioneering book, Rhythmic Swimming, is a classic textbook on the sport she originated.

Over the next 30 years more and more countries began developing synchro clubs as well as college teams. One of the most famous venues was the University of Chicago’s water ballet club, started by Katherine Curtis. In 1934, sixty of Curtis’ Modern Mermaids swam in the lagoon at the Century of Progress World’s Fair in Chicago using what they called, “a combination of strokes, tricks and floating formations.” The event received rave reviews, and an announcer at the event coined the term “synchronized swimming” for the first time.

Hollywood also helped the cause of synchro by discovering Esther Williams, a swimming champion and Olympic contender. She starred in movies that featured synchronized swimming like Million Dollar Mermaid. Her fame on screen placed synchro in the heart of American pop culture in the 1940s and 1950s. This lead to an increase of competitions until, after being a demonstration sport for a number of years, synchro made it as a true competition in the 1984 Los Angeles Olympics. It is still a local, regional, national, international, and Olympic sport to this day.

Synchro incorporates theme music, costumes, swimming choreography, precise timing, and graceful movements in their arms, figures, and highlights. Those that participate in synchro are true athletes, strong swimmers, and elegant performers. To perform their sections, they need to be proficient in various swimming skills, including swimming strokes; breath-holding and rhythmic breathing; forward, backward, and stationary sculling; head and feet-first surface diving; eggbeater kicking; changing positions in the water; treading water; etc.

There are three main events in synchro: solo, duet, and team. As each name suggests, solo consists of a single synchronized swimmer; duets have two swimmers who are synchronized with each other as well as the music; and team consists of usually 4-8 swimmers synchronizing with each other and the music.

Judges evaluate synchro with scores from 0 to 10 in two categories: technical merit and artistic interpretation. Technical merit is comprised of the form of swimming strokes, propulsion techniques, figures, patterns and transitions, synchronization with the other swimmers and the music, and difficulty. Artistic impression consists of the variety and creativity of movements and transitions, fluidity, patterns and pool usage, music interpretation, poise in presentation, ability to communicate through choreography, and seeming effortlessness of the performance. Half of the judges mark technical merit and the other half mark artistic impression.

Click here to go to the USA Synchronized Swimming website.

To view training videos by Ymajahi Brooks for Expert Village (2008), click these links:

To view a few additional training videos, click these links:

How to Do a Boost (Elizabeth with VideoJug)
Synchronized Swimming Workshop (SwimTechnique.TV)-Lots of interesting shots above and below water
Sculls for Synchro-17 short videos (Synchronized Swimming Channel)
Short Warm-up for Synchro (Synchronized Swimming Channel)

To view world-class synchro in action, check out these links from past Olympic Games:

syncope

A temporary loss of consciousness, also described as passing out or fainting, due to the sudden decline of blood flow to the brain. For more information, go toSyncope (Fainting).

systole

The contraction phase of the normal heart cycle during which blood is driven into the aorta and pulmonary artery.

systolic blood pressure

The highest blood pressure measured in the arteries that occurs during the pumping phase of each heartbeat. It is measured in millimeters of mercury (mm Hg) and is the upper number in the standard blood pressure reading. For example, in a blood pressure reading of 120/80, 120 refers to the systolic blood pressure.

T

tachycardia

A heart rate that’s too fast. Tachycardia is often defined as a heart rate that’s more than 100 beats per minute in adults.

target heart rate

The minimum heartbeats in a given amount of time to reach the level of exertion necessary for cardiovascular fitness, specific to a person’s age, gender, and physical fitness. This is usually 60% to 85% of the estimated maximum heart rate, which is determined by subtracting your age from 220.

their

(1) Of or relating to them or themselves especially as possessors, agents, or objects of an action. (2) Of or relating to him or her or himself or herself (as an indefinite third-person singular antecedent) especially as possessor, agent, or object of an action.

This term has been included here because there are many instances where an indefinite third-party singular pronoun is needed in safety writing. “The lifeguard should remain in his or her station for the duration of his or her shift” becomes the less awkward “The lifeguard should remain in their station for the duration of their shift.” Although the indefinite third-person singular pronoun can also be avoided, “their” in this case is becoming more accepted and will be used as appropriate on this website and in related documents. To avoid the indefinite third-party singular pronoun, you can do one of the following:

“You should remain in your station for the duration of your shift.”
“Lifeguards should remain in their station for the duration of their shift.”

To see what Merriam Webster has to say about the use of “their” as an indefinite third-person singular pronoun, go to The Awkward Case of ‘His or Her’.

thermocline

A thin but distinct layer in a large body of fluid (e.g., water, such as an ocean or lake, or air, such as an atmosphere) in which temperature changes more rapidly with depth than it does in the layers above or below.

3-3

A code name used by NASCO for a drowning victim who is 3 years old or less in 3 feet of water or less.

throw bag

A rescue device used for throwing assists consisting of a bag, a line of rope with one end attached to the inside of the bag, and a foam disk at the base of the bag. To use the device, make sure the rope is stuffed carefully in the bag so it will not be tangled. Loosen the top of the bag so the rope can come out, hold the bag by its handle, aim the bag at the victim, and toss it a little beyond the victim. Instruct the victim to hold onto the rope (not the bag) and pull the victim to safety.

For instructions on throw bag use, check out these links:

Tossing a Throw Bag (NRS)
Tossing a Throw Bag (Rescue Methods)-Excellent! This includes 3 types of throws, restuffing (visual only), and re-throws using the line.
Wedge Throw Bag (NRS)-Very compact throw bag. Great choice to carry with you or to have on the deck.

Here are instructions for re-stuffing the throw bag (NRS)

throwing assist

lifesaving-ringbuoy 222 — Ring buoy in flight

A method of helping someone out of the water by throwing a floating object usually with a line attached from a position of safety on the deck, dock, shore, or boat and then pulling the person to safety. It is part of the mantra for nonlifeguard rescuers (designed to keep them safe while they are helping others): “Reach or throw; don’t go.”

Objects commonly used to make a throwing assist include:

Heaving jug
Life ring or ring buoy
Line of rope (throw line) with or without a monkey’s fist
Rescue tube
Seat cushion PFD
Throw bag

To see throwing assists performed, check out the following links:

Using a Life Ring (and Attaching It to a Boat) (SV HideAway)-Be patient! It is interesting to see the life ring used with a power boat.
Reach or Throw; Don’t Go (American Red Cross)
Reach, Throw, Row; Don’t Go (US Army Corp of Engineers)
Performing a Speed Line Throw (RLSS UK)
Tossing a Throw Bag (NRS)
Tossing a Throw Bag (Rescue Methods)-Excellent! This includes 3 types of throws, re-stuffing (visual only), and re-throws using the line.
Tying a Monkey’s Fist for a Throwing Line (Repairs101)-A monkey’s fist knot enables you to throw a line a greater distance with accuracy.
Quickly Recoiling a Throw Line or Throw Bag Line (NRS)

throw line

A line attached to a throwing device such as a ring buoy or heaving jug so that a victim can be pulled to safety. A throw line may have a weighted monkey’s fist at the end to be used in mooring a boat or casting a line for any purpose, including water rescue.

Here are some videos related to throw lines:

Tying a Monkey’s Fist for a Throwing Line (Repairs101)-A monkey’s fist knot enables you to throw a line a greater distance with accuracy.
Quickly Recoiling a Throw Line or Throw Bag Line (NRS)
Throwing a line (RLSS UK)-Nice technique, great accent!

thunderstorm

A type of storm characterized by the presence of thunder and lightning. Sometimes known as an electrical storm, a lightning storm, or a thundershower, thunderstorms occur in association with cumulonimbus clouds. In addition to thunder and lightning, thunderstorms are usually accompanied by strong winds, heavy rain, and sometimes snow, sleet, hail; they can also feature no precipitation at all.

Thunderstorms result from the rapid upward movement of warm, moist air. As the warm, moist air moves upward, it cools, condenses, and forms cumulonimbus clouds that can reach heights of over 12 miles (20 km). Water droplets and ice form and begin falling towards the Earth’s surface. On the way down, the droplets collide with other droplets and become larger. The falling droplets create a downdraft of cold air and moisture that spreads out at the Earth’s surface, causing the strong winds and occasionally fog, both commonly associated with thunderstorms.

Thunderstorms can generally form and develop in any particular geographic location, perhaps most frequently within areas located at mid-latitude when warm moist air collides with cooler air. Thunderstorms are responsible for the development and formation of many severe weather phenomena. Thunderstorms, and the phenomena that occur along with them, pose great hazards to populations and landscapes. Damage that results from thunderstorms is mainly inflicted by downburst winds, large hailstones, and flash flooding caused by heavy precipitation. Stronger thunderstorm cells are also capable of producing tornadoes and waterspouts.

If outdoors in a thunderstorm:

Watch the sky for dangerous weather like darkening clouds, increases in winds, lightning flashes, and sounds of thunder. If you can hear thunder, you can be struck by lightning.
Seek shelter in a sturdy building or motor vehicle. Avoid gazebos, picnic shelters, sheds, or trees. If in a motor vehicle, make sure all the doors and windows are shut and avoid touching the metal frame. Stay in the shelter until 30 minutes after the last sound of thunder or flash of lightning.
If there is no shelter nearby, stay away from trees (at least twice the distance that the trees are tall). If you are in a group, spread out so that each person is at least 15 feet away from everyone else. Crouch down on your feet in the open area and place hands over your ears to avoid hearing damage.
Stay out of water. Do not swim, wade, snorkel, or scuba dive. Do not crouch down in a puddle.
Avoid metal. Stay away from bleachers, clotheslines, dugouts, fences, phone booths, etc. Drop anything you are carrying with metal components like a backpack, briefcase, or purse.

If indoors in a thunderstorm:

Avoid water. Don’t swim, take a shower, wash your hands, or do laundry.
Do not use a corded telephone. Lightning can strike the phone lines.
Avoid electrical equipment/electronics. Do not use the computer, appliances, etc.
Remain sheltered. Avoid windows and doors. Stay off porches.

If someone is struck by lightning:

Call 911 or the local emergency number. Regardless of the patient’s condition (conscious, unconscious, injured, uninjured, etc.), consider this a life-threatening emergency.
Remember scene safety. If you are out in the open, consider the possibility of carefully moving the patient to shelter. The patient does not carry a charge; it is safe to touch the patient.
If you do not have to move the patient, have the patient remain still. A lightning strike can cause broken bones and internal injuries that you may not be able to see.
Monitor the patient’s vital signs. Be prepared to give CPR if the patient stops breathing.
Treat the patient for shock by keeping the patient from getting chilled or overheated, by treating any injuries, and by staying with the patient and giving comfort and reassurance.

For more information about thunderstorms and thunderstorm safety, follow these links:

Lightning (Weather Wiz Kids)
Severe Weather 101: Thunderstorm (NSSL: NOAA)
Thunderstorm Safety (American Red Cross)
Thunderstorm Safety (Weather Wiz Kids)
Thunderstorms and Lightning (Ready.gov)

Title 22 First Aid

A 21-hour, comprehensive first aid/CPR/AED program (also known as First Aid for Public Safety Personnel) required by the State of California for public safety personnel, specifically firefighters, lifeguards, and peace officers. The name “Title 22” First Aid refers to the location of the law which describes the program in the California Code of Regulations, Title 22, Division 9, Chapter 1.5, Articles 1–4.

This law has been a requirement in California since 1987. It was significantly revised on February 25, 2015.

tornado

A violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. Often referred to as twisters, tornadoes come in many shapes and sizes but are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust. The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (480 km/h), stretch more than two miles (3 km) across, and stay on the ground for miles (more than 100 km).

Various types of tornadoes include the landspout, multiple vortex tornado, and waterspout. Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirl, and steam devil; downbursts are frequently confused with tornadoes, though their action is dissimilar.

Tornadoes have been observed on every continent except Antarctica. However, the vast majority of tornadoes occur in the Tornado Alley region of the United States.

Several scales exist for rating the strength of tornadoes. The Fujita Scale and Enhanced Fujita Scale rate tornadoes by damage caused. For example, an F0 or EF0 tornado (the weakest category) damages trees but not substantial structures. An F5 or EF5 tornado (the strongest category) rips buildings off their foundations and can deform large skyscrapers. The similar TORRO Scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. Doppler radar data, photogrammetry, and ground swirl patterns may also be analyzed to determine intensity and assign a rating.

Tornadoes_Globdist_PD — Global distribution of tornadoes

Though tornadoes can strike in an instant, there are precautions and preventative measures that people can take to increase the chances of surviving a tornado. The meteorological agencies in some countries distribute tornado forecasts and increase levels of alert of a possible tornado (such as tornado watches and tornado warnings in the United States and Canada). Weather radios provide an alarm when a severe weather advisory is issued for the local area, though these are mainly available only in the United States.

Authorities such as the Storm Prediction Center advise having a predetermined plan should a tornado warning be issued. When a warning is issued, going to a basement or an interior first-floor room of a sturdy building greatly increases chances of survival. In tornado-prone areas, many buildings have storm cellars on the property. These underground refuges have saved thousands of lives.

Unless the tornado is far away and highly visible, meteorologists advise that drivers park their vehicles far to the side of the road (so as not to block emergency traffic), and find a sturdy shelter. If no sturdy shelter is nearby, getting low in a ditch is the next best option. Highway overpasses are one of the worst places to take shelter during tornadoes, as the constricted space can be subject to increased wind speed and funneling of debris underneath the overpass.

To learn more about tornadoes, follow these links:

FAQ: Tornadoes (NOAA)
Severe Weather 101: Tornadoes (NSSL: NOAA)
Tornado Detection and Warning (NOAA)
Tornadoes (Ready.gov)
What We Know and Don’t Know About Tornado Formation (Physics Today)

Tornado Alley

An area of the United States where tornadoes are most frequent.

The term was first used in 1952 as the title of a research project to study severe weather in parts of Texas, Oklahoma, Kansas, South Dakota, Iowa, Missouri, New Mexico, Colorado, North Dakota, and Minnesota only. It is largely a media driven term although tornado climatologists distinguish peaks in activity in various areas and storm chasers have long recognized the Great Plains tornado belt.

Although the boundaries of Tornado Alley are not clearly defined, its core extends from northern Texas, Oklahoma, Kansas, into Nebraska. Some research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.

Outside of Tornado Alley in the central and southern US, the Pampas lowlands of Argentina extending into adjacent areas of Paraguay and extreme southern Brazil and Bangladesh and adjacent East India have the highest frequency of violent tornadoes.

tornado emergency

An enhanced version of the tornado warning used by the National Weather Service (NWS) in the United States, during significant tornado occurrences in highly populated areas. Although it is not a new warning type from the NWS, a tornado emergency generally means that significant, widespread damage is expected to occur with a high likelihood of numerous fatalities due to a large, strong to violent tornado. A tornado emergency may also be issued when computer models predict a 100% chance that a powerful tornado will strike a populated area.

tornado warning

An alert issued by national weather forecasting agencies to warn the public that severe thunderstorms with tornadoes are imminent or occurring. It can be issued after a tornado or funnel cloud has been spotted by the public or law enforcement or when there are radar indications of tornado formation. The issuance of a tornado warning indicates that residents should take immediate safety precautions. It is a higher level of alert than a tornado watch, but it can be surpassed by an even higher alert known as a tornado emergency.

tornado watch

An alert issued when weather conditions are favorable for the development of severe thunderstorms that are capable of producing tornadoes. A tornado watch therefore implies that it is also a severe thunderstorm watch. A tornado watch must not be confused with a tornado warning. In most cases, the potential exists for large hail and damaging winds in addition to tornadoes.

A watch does not mean that the severe weather is actually occurring, only that atmospheric conditions have created a significant risk for it. If severe weather actually does occur, a tornado warning or severe thunderstorm warning would then be issued.

total coverage

Lifeguard service in which a single lifeguard supervises the entire swimming pool or swimming area. This type of coverage is used during times of low attendance, such as during lap swimming, swimming lessons, or swimming pool rental for parties and special events.

track start

A racing start in which the hands grasp the front of the starting block and the feet are staggered on the block.

training

(1) An informal or organized process by which someone is taught the skills that are needed for an art, profession, or job, (2) the process by which an athlete prepares for competition by exercising, practicing, etc.

traveler’s diarrhea

A digestive tract disorder that commonly causes loose stools and abdominal cramps. It is caused by eating food or drinking water contaminated with human bowel waste. According to the Centers for Disease Control and Prevention (CDC), traveler’s diarrhea (also spelled travelers’ diarrhea) is the most common travel-related illness. It can occur anywhere, but the highest-risk destinations are in most of Asia (except for Japan) as well as the Middle East, Africa, Mexico, and Central and South America.

Traveler’s diarrhea is sometimes defined as 3 or more loose bowel movements within a 24-hour period. To care for this condition, drink plenty of fluids, take antibiotics for the infection, and over-the-counter medication to treat the symptoms of diarrhea.

To prevent traveler’s diarrhea, eat and drink safely when traveling and keep your hands clean. To eat and drink safely, eat only food that is cooked and served hot. Eat raw fruits and vegetables only if you have washed them in clean water or peeled them. Drink only beverages from factory-sealed containers, and avoid ice (because it may have been made from unclean water).

To learn more about traveler’s diarrhea, follow these links:

treading water

A basic aquatic skill that enables a swimmer to hold position at the surface of deep water in a vertical position with head out of the water by combining sculling arm movements and a scissors, breaststroke, or eggbeater kick.

tree well

A void or area of loose snow around a tree trunk that can trap hikers, snow skiers, etc. who get too close. Also called a “spruce trap.” Anyone trapped in a tree well may suffocate in the snow (snow immersion asphyxiation) or suffer hypothermia or severe frostbite.

If sucked into a tree well or deep bank of snow, try to tuck, roll, and land upright (to avoid ending up head down in the snow). If possible, grab a tree branch and yell to others with you or around you. If buried upside down, stay calm and create an air pocket, which may buy you some precious minutes of breathing time while waiting to be found.

For more information about tree well hazards, see snow immersion asphyxiation.

Trudgen crawl

A variant of the Trudgen stroke that uses a scissor, flutter, flutter, scissor kick to each arm cycle instead of the single large scissors kick used in the Trudgen stroke with the swimmer is breathing.

Trudgen stroke

A stroke variant and predecessor of the front crawl or freestyle, developed in 1875 by John Trudgen, an Englishman, after observing South American Indian swimming a similar stroke (although the indians used a type of flutter kick and Trudgen used a scissors kick when breathing instead). Swimming for the Alliance Swimming Club of London, Trudgen won the English 100 yards Championships at the Edghaston Reservoir with a time of 1 minute and 16 seconds.

The Trudgen stroke became popular quickly, but by 1920, most competitive swimmers had adopted the front crawl, which incorporated a flutter kick.

To perform the Trudgen, use an arm-over-arm stroke as with the front crawl, but allow the legs to drag in the water until rolling your body and turning the head to breathe. As you breathe, perform a single scissors kick, top leg going forward and bottom leg going backwards. Breathe and kick every stroke cycle. To see a demonstration of the Trudgen, check out Phillip Toriello’s Trudgen. (NOTE: The stroke does not have to be swum head-up, but since the Trudgen is inadvertently used by water polo players and body surfers the a quick thrust forward when starting to swim, this may explain why he shows it head-up.)

For another demonstration, here is a silent picture showing the evolution of swimming that includes the Trudgen (although they misspell the name).

Variants of the Trudgen stroke include the double Trudgen (2 smaller scissors kicks per stroke cycle or 1 kick per stroke) and the Trudgen crawl (the kick is as follows: 1 small scissors kick to one side, 2 flutter kicks, 1 small scissors kick to the other side during each stroke cycle).

tuck position

A diving position in which the body is bent at the hips and knees, with the thighs drawn to the chest and the heels kept close to the buttocks.

tuck surface dive

A head-first dive from the surface of the water performed from a swimming position on the front by bending the legs at the hips and knees, rotating the head and chest underwater, and then extending the legs up and out of the water to use the weight of the legs to cause the body to descend.