Preventing Heat-Induced Death and Illness

Heat-related illnesses cause more than 600 deaths in the U.S. each year.[1] Many of these deaths could have been prevented by drinking much more fluid than needed to simply quench thirst and by engaging in other heat-coping behaviors.

In hot weather, certain higher-risk groups must take extra precautions; these groups include:[2]

• children up to 4 years old;
• adults 65 and older;
• people taking medicines that cause fluid loss;
• people less able to care for themselves because of chronic mental illness or dementia;
• people who are overweight or obese;
• people with chronic diseases, especially cardiovascular disease or diabetes; and
• people who work in excessively hot conditions without adequate safety precautions.

Cooling caused by the evaporation of sweat is a natural, necessary phenomenon, and it is the only way people who do not have air conditioning can survive in very hot weather. Many drugs can impair the body’s ability to get rid of excessive heat or cause fluid loss and, thus, put patients at increased risk of heatinduced illness.

Safeguards to prevent heat-related injury include increased efforts to keep cool, drinking more fluids and closer observation by others for early signs of heat illness. People at higher risk for heat illness are more likely to build up dangerous levels of body heat, which may lead to one of the heat-related conditions discussed in the following sections.

Heat exhaustion and heat stroke[3]

Heat exhaustion results from prolonged exposure to heat and a subsequent loss of body fluids and salt, usually through excessive sweating. The signs and symptoms of heat exhaustion are headache, nausea, dizziness, weakness, irritability, thirst, heavy sweating, elevated body temperature and decreased urination. Heat exhaustion is treated by lying down away from the source of heat; removing unnecessary clothing, including shoes and socks; cooling down with cold compresses; washing the head, face and neck with cold water; and slowly drinking cool fluids.

If heat exhaustion is severe and not adequately treated, then heat stroke — a life-threatening medical emergency — can occur. In the event of a heat stroke, the body rapidly loses the ability to control its temperature and is no longer able to sweat. The body’s temperature can rise to 106°F or higher within 10 to 15 minutes. Symptoms of heat stroke include confusion, slurred speech, hot and dry skin, profuse sweating, seizures or loss of consciousness (coma). People experiencing the onset of heat stroke should seek immediate medical attention by calling 911; first-aid treatment similar to that recommended for heat exhaustion should be given in the meantime.

Other heat-related illnesses[4]

Heat syncope is dizziness, lightheadedness or fainting that results from prolonged standing or sudden rising from a sitting or lying position in a hot environment. It is more likely to occur when a person is dehydrated and not acclimated to the hot weather. Heat syncope is treated by sitting or lying in a cool place and slowly drinking fluids.

Prolonged physical exertion in hot weather can lead to muscle cramps and, in severe cases, a life-threatening condition known as rhabdomyolysis, which involves rapid breakdown and death of muscle tissue. Symptoms of rhabdomyolysis include severe muscle cramps or pain, dark (tea- or cola-colored) urine and weakness. Stopping physical activity, drinking fluids and seeing a medical professional immediately is essential when such symptoms occur.

Examples of Drugs That Can Impair Your Response to Heat

References

[1] Centers for Disease Control and Prevention. Heat-related illness: Picture of America report. https://www.cdc.gov/pictureofamerica/pdfs/picture_of_america_heat-related_illness.pdf. Accessed April 6, 2018.

[2] Centers for Disease Control and Prevention. Heat-related illness: Picture of America report. https://www.cdc.gov/pictureofamerica/pdfs/picture_of_america_heat-related_illness.pdf. Accessed April 6, 2018.

[3] Ibid. PDF p. 2

[4] Centers for Disease Control and Prevention. Heat stress – Heat-related illness. https://www.cdc.gov/niosh/topics/heatstress/heatrelillness.html. Accessed March 15, 2018.

[5] Ibid.