These range in seriousness from the least incapacitating, heat fatigue , to heat cramps and heat exhaustion, to the most dangerous, heat stroke , sometimes known as sunstroke . As more blood flows through the enlarged vessels, the excess heat passes into the cooler air. If this is not enough to cool the blood, the sweat glands begin to pour out water. But when the air temperature rises, the blood does not cool as it circulates through the skin. When you overtax the body's cooling mechanism, you risk heat illness.
Heat stroke is an emergency that requires medical assistance as soon as possible.
While waiting for an ambulance, take steps to lower body temperature, such as wiping alcohol or cold water on the skin . In an ordinary summer in the United States some 175 people die from an overdose of heat and sun. During the heat waves of recent years over 1,000 people a year died in the United States as a result of heat-related illnesses. Symptoms you are likely to notice It is important to be able to recognize the differences among the four levels of heat illness. Heat stroke can kill quickly if not treated.