heat exhaustion

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Fatigue caused by prolonged exposure to environmental heat. Sufferers of heat exhaustion usually have a normal body temperature but their pulse rate is accelerated, their skin is cold and sweaty, and they often experience drowsiness and vomiting. The condition can be prevented by drinking plenty of water. Heat exhaustion is usually relieved by rest and cooling, but if it persists there is a risk of heat neurasthenia developing. Heat neurasthenia is a progressive condition characterized by feelings of apathy, hysteria, and aggression. It can lead to chronic behaviour disorders. Compare heat stroke.

Fatigue caused by an inability of the cardiovascular system to satisfy all of the requirements of the body's tissues when blood is shifted to the skin for cooling. Typically, those suffering from heat exhaustion have a normal body core temperature, but their pulse rate is accelerated, their skin is cold and clammy, and they often experience drowsiness and vomiting. The condition can be alleviated by rest and cooling with tepid water, but if it persists there is a risk of heat neurasthenia. Heat exhaustion can usually be prevented by regular water replacement.