Heat Exhaustion (cont.)
What causes heat exhaustion?
Heat exhaustion occurs when a person exercises and works in a hot environment and the body cannot cool itself adequately. Dehydration occurs with water loss from excessive sweating, which causes muscle cramps, weakness, and nausea and vomiting. This makes it difficult to drink enough fluid to replenish the body's water supply, and the lack of body water impairs further sweating, evaporation and cooling.
Relative humidity is an important factor in developing heat exhaustion. If the humidity is too high, sweat on the skin cannot evaporate into the surrounding air and body temperature cooling fails.
Living in a hot environment may predispose a person to heat exhaustion. During a heat wave, the elderly, the poor, and those who live an isolated life may not have access to air conditioning and are at risk of heat-related illnesses.