SPORTS AND ATHLETICS: HEAT DISORDERS

Heat disorders are a group of physical disorders brought on by prolonged exposure to hot temperatures, insufficient fluid intake, and failure of the body to successfully regulate its internal temperature. Heat disorders, which usually result in hyperthermia, include heat cramps, heat exhaustion and heat stroke. These conditions can be serious and even life-threatening if prompt action is not taken to manage them. Heat disorders are especially serious in older people.

Heat Cramps

The least severe of the three heat disorders, heat cramps are the first sign that the body is having trouble coping with increased temperatures. These painful, involuntary muscle spasms usually occur when a person is exercising heavily in a very hot environment. Excessive perspiration (electrolyte loss) and insufficient fluid intake also contribute to the problem. The muscles most commonly affected include those in the calves, abdomen and arms.

Treatment of heat cramps consists of moving out of the sun or the hot environment and resting, drinking water or sports drinks, and gentle stretching and massage.

Heat Exhaustion

This is a more serious and complex condition. Like heat cramps, heat exhaustion is linked to heavy exercise, high temperatures, excessive perspiration and inadequate fluid intake. However, symptoms come on suddenly and resemble those of shock. They include nausea, faintness, a rapid heartbeat, low blood pressure, a low-grade fever or a subnormal body temperature, ashen appearance, and cool, moist, pale skin. Heat exhaustion requires prompt attention; otherwise, it can develop into the still more serious heat stroke. People who have symptoms of heat exhaustion must be moved from the sun into the shade (or from the hot environment to a cooler area) and carefully laid down with their legs slightly elevated. Every effort must be made to lower the person's body temperature. This includes having the person drink cool (not cold) fluids such as water or sports drinks; loosening clothing; and fanning the person and spraying him or her with cool water. If the fever rises above 104°F, or if symptoms such as fainting, confusion or seizures develop, immediate emergency medical assistance should be sought.

Heat Stroke

Also known as sunstroke or heat hyperpyrexia, heat stroke is a severe and potentially fatal condition. Sunstroke is a type of heat stroke. As with other heat disorders, it can occur when a person exercises or works too strenuously in hot weather or a hot environment without replenishing body fluids. Particularly susceptible to heat stroke are older people and individuals who have an impaired ability to sweat. Other risk factors include obesity, alcohol use, dehydration and cardiovascular disease.

The primary symptom of heat stroke is a spike in temperature to greater than 104°F. When a person experiences heat stroke, he or she loses the normal mechanisms for coping with heat stress, such as temperature control and sweating. Fainting is often the first symptom in older people. Other signs include hot, dry skin; rapid heartbeat; rapid and shallow breathing; low blood pressure; irritability; and cessation of sweating. Changes in mental status range from personality changes to confusion to, rarely, coma. Immediate emergency medical assistance is required. In the meantime, individuals should be cooled down as much as possible.

Excerpted from: Complete Medical Encyclopedia, American Medical Association, 2003.