If the body is not cooled at this point, heat stroke may follow. Heat stroke causes blood clots and heart failure. Without proper treatment, heat stroke is fatal 80 percent of the time. To avoid the ill effects of high heat, increase water consumption well before the onset of thirst. Alcoholic beverages are discouraged in high heat conditions because they cause dehydration.
Fruit juices are a good substitute for water, and if exercising, sports drinks are encouraged.
Conduct outdoor work or exercise in the early morning or evening when it is cooler. Wear light-colored, loose fitting clothing that permits the evaporation of perspiration. A wide brimmed hat helps prevent sunburn as well as heat related illness. Take frequent cool baths or showers. Never leave a person or a pet inside a closed car with no ventilation.