Preventing Heat-Induced Death and Illness

During hot summers, as many as 1,000 unnecessary deaths in the U.S. are caused by heat stress. Many of these deaths can be prevented by drinking much more fluid than is needed to simply quench thirst (the cooling caused by the evaporation of sweat is the only way people who do not have the luxury of air conditioning can survive in very hot weather) and by engaging in other heat-coping behaviors.

In hot weather, extra precautions must be taken for certain higher-risk groups, including:

• infants younger than 1 year old
• people over 65 years old
• people less able to care for themselves because of chronic mental illness or dementia of any cause
• people with chronic diseases, especially cardiovascular or kidney disease
• people taking any of the drugs listed in the table on pages 6 and 7
• people who work in excessively hot conditions without adequate safety precautions (at least 523 U.S. workers have been killed over the past two decades from heat stress, the subject of a 2011 Public Citizen petition available at www.citizen.org/petition-to-osha-for-a-heat-standard-2011)

Safeguards may include increased efforts to keep cool or 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 following three heat-related conditions.

Heat exhaustion

The most common form of illness due to hot weather is heat exhaustion. This condition takes longer to develop than other heat-related illnesses and results from a loss of body fluids and salt. The symptoms of heat exhaustion are thirst, fatigue, giddiness, elevated body temperature and, in severe instances, delirium. When both body water and salt are depleted, muscle cramps may also be present.

Heat exhaustion is treated by resting in bed, away from the heat, and restoring body water by drinking cool fluids, taking alcohol sponge baths (on the advice of a physician) or applying wet towels to the body.

Heat syncope (faintness, dizziness)

Heat syncope results from sudden increased exertion or a lack of acclimation to hot weather. The condition is marked by dizziness, fatigue and sudden faintness after exercising in the heat. Other symptoms include cool, sweaty, pale skin; weak pulse; and falling blood pressure.

In contrast to heat stroke (discussed in the next section), heat syncope is often resolved by removing the victim from direct heat exposure. The best additional treatment involves resting (lying or sitting down with the head lowered), cooling off and drinking extra liquids.

Drugs That Can Impair Your Response to Heat

* Do Not Use
** Limited Use (offers limited benefit or benefits certain people or conditions)
Note: This table is not an exhaustive list. Consult your doctor to ensure that you are not taking a drug that can impair your response to heat. Many of the drugs mentioned here are also in combination products or in other dosage forms not listed. Check with your doctor or pharmacist to ascertain if any of the drugs you are taking contain any of these drugs. Many heart drugs contain hydrochlorothiazide.
 

Heat stroke

A life-threatening medical emergency, heat stroke or collapse requires immediate attention by a doctor or other properly trained medical personnel. The symptoms of heat stroke include faintness, dizziness, staggering, headache, nausea, loss of consciousness, high body temperature (104 degrees Fahrenheit / 40 degrees Celsius or higher), strong rapid pulse and flushed skin. In severe cases, blood pressure drops as circulation fails, and death can ensue.

What You Can Do

Because body heat can continue to build up for days after a heat wave ends, doctors and others who care for the elderly or the ill should monitor body temperatures closely during and after periods of extreme heat.

If you are taking any of the drugs listed in the tables above, it is even more important that you follow the guidelines in the “Ways to Avoid Heat- Induced Death and Illness” box.

Much of the information in this article defining heat exhaustion, heat syncope and heat stroke was published in 1980 in the Centers for Disease Control and Prevention bulletin Morbidity and Mortality Weekly Report following a complaint by Public Citizen’s Health Research Group that the government had given out dangerously incomplete information about how to survive the heat. The list of drugs has been updated periodically, including for this article.