Premergency First Aid, CPR and AED Manual

9 Other Emergencies

Heat Exposure The body has complicated internal mechanisms that attempt to keep body temperature at approximately 37°C (98°F). In hot climates or during exercise, when the body produces excess heat, these mechanisms work to keep the body cool. One way the body does this is through sweating and the evaporation of sweat. The other is by dilating (making bigger) the blood vessels of the skin. When the ability to decrease body heat is lost, illness develops. Different factors affect the body’s ability to cool effectively. High air temperature reduces the body’s ability to lose heat by radiation and high humidity reduces the body’s ability to lose heat by evaporation. Lack of acclimation to the environment and vigorous exercise are both risk factors. The body can sweat over 1 liter of fluid per hour while exercising causing loss of both electrolytes and fluid.

Illness from heat exposure has three forms: • Heat cramps • Heat exhaustion • Heatstroke

It is possible to encounter all three injuries in the same patient. Heat exhaustion, left untreated, can progress to heatstroke, a life-threatening emergency. Infants and older people are at greater risk of hypothermia as are people with illnesses such as heart disease, COPD, diabetes, and obesity. Dehydration is a factor in heatstroke and alcohol, and certain medications may promote dehydration and inhibit sweating. Certain medications may also make a person more susceptible to heat illness. Remember to get medication information when obtaining the patient history.

362

www.preohs.com