By Robin Westen
Blistering summer heat waves can be not only extremely uncomfortable, but even deadly, as we’ve learned this summer. Literally hundreds of people across the United States have died from heat or heat-related causes.
History shows that heat waves are deadliest in large cities that rarely experience hot weather, with the elderly and those in poor health in the greatest danger.
In recent years, scientists have learned that a day's highest temperature is not the best measure of the danger of heat waves. Unrelenting heat that doesn't allow people to rest at night is responsible for the deaths of many elderly and ill people. Recognition of this led the U.S. National Weather Service to begin using a new mean heat index—a measure of how hot the temperature feels to a person over the course of a day.
The elderly and ill aren't the only people that heat kills. It also kills healthy young people, usually because they do not recognize the dangers of exercising in hot weather, especially hot, humid weather.
When heat and humidity combine to slow evaporation of sweat from the body, outdoor exercise becomes dangerous even for those in good shape. Overheating can cause serious, even life-threatening conditions such as heat stroke.
Key rules for coping with heat are to drink plenty of water to avoid dehydration and to slow down and cool off when feeling fatigued. Other trouble signs: a headache, a high pulse rate or shallow breathing.
Dangers of heat include
Heat cramps:Exercising in hot weather can lead to muscle cramps, especially in the legs, because of brief imbalances in body salts
Heat syncope or fainting:Anyone not used to exercising in the heat can experience a quick drop in blood pressure that can lead to fainting. As with heat cramps, the cure is to take it easy.
Heat exhaustion:Losing fluid and salt through perspiration or replacing them in an imbalanced way can lead to dizziness and weakness. Body temperature might rise, but not above 102 degrees. In some cases victims, especially the elderly, should be hospitalized. Heat exhaustion is more likely after a few days of a heat wave than when one is just beginning. The best defense is to take it easy and drink plenty of water. Don't take salt tablets without consulting a physician.
Heatstroke:In some cases extreme heat can upset the body's thermostat, causing body temperature to rise to 105 degrees or higher. Symptoms are lethargy, confusion and unconsciousness. Even a suspicion that someone might be suffering from heatstroke requires immediate medical aid. Heatstroke can kill.
The bottom line: Play it safe, no matter how excessively cautious that might seem. Even if you’re staying indoors, make sure your air-conditioning is turned down low enough, and don’t be afraid to ask for help if you feel overwhelmed by heat. (And if you've got outdoor pets, bring them inside for a while. Animals feel heat, too.)
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Robin Westen is ThirdAge's Medical Director. Check for her daily updates. Her latest book, co-authored with Dr. Alyssa Dweck, is "V is for Vagina."