The human body keeps itself at a constant core temperature. Although the “accepted” average normal body temperature is 98.6°F (37.0°C), normal body temperature varies from person to person, from body part to body part, and from hour to hour during the day. Thus, an oral temperature reading between 97.7°F and 99.5°F (36.5°C and 37.5°C) is most likely normal.
The body temperature control center is in the brain; it is called the hypothalamus. The hypothalamus receives information about body temperature and makes adjustment accordingly to keep body temperature within an acceptable range. This is important since the cells of the body cannot stay alive and healthy for long outside of the normal range. Click the link for more details on body temperature.
How the Body Regulates Temperature
Thermoregulation is the ability of the body to keep its temperature within a certain range, even when the surrounding temperature is very different. If the body is unable to maintain its normal temperature, a heat- or cold-related emergency can result.
Heat is a byproduct of metabolism, the conversion of food into energy. Most body heat is generated in the deep organs, especially the liver, brain, and heart. In addition, the body also gains heat by shivering or any kind of physical activity. You assist in the maintenance of an appropriate body temperature by wearing appropriate clothing, minimizing exposure to harsh environments, staying hydrated, becoming acclimated over time, etc.
The skin assists in maintaining normal body temperature by reacting differently to hot and cold conditions so that the inner body temperature remains more or less constant. Vasodilation and sweating are the primary modes by which humans attempt to lose excess body heat. Alternatively, vasoconstriction occurs in cold environments to reduce the amount of blood near the surface thereby retaining heat in the body’s core.
Heat-Related Emergencies
Several illnesses and other conditions can occur due to the overheating of the body. Here is a FAQ about exposure to extreme heat by the CDC. Heat-related illnesses can happen to anyone but the following contributing factors make a heat-related illness more likely: high humidity; strenuous activity; being young or old; having preexisting conditions like diabetes, heart disease, or obesity; and drug use.
- Dehydration
- Heat cramps
- Heat rash
- Heat exhaustion
- Heat stroke
Cold-Related Emergencies
A cold-related emergency can be a generalized or localized condition. When the cold environment cause a critical drop in core body temperature, this generalized condition is known as hypothermia. Factors that contribute to hypothermia include the temperature; humidity; the presence of wind or water; the age of the patient; inappropriate clothing; alcohol and drug use; and medical conditions like shock, infection, hypoglycemia, etc.
Localized cold-related emergencies include frostnip, superficial frostbite, and deep frostbite. These conditions involve the freezing of body tissue.
- Hypothermia and cold water survival
- Localized cold-related emergencies (frostbite, etc.)