A recent report from South Africa shows that the most likely cause of death during hot weather sports events is heat stroke, when the body temperature rises so high that it cooks the brain ( Medicine and Science in Sports and Exercise , July 2008). The treatment for a person who collapses from heat stroke is immediate immersion in cold water.
An excessive rise in body temperature is caused either by producing too much heat or by inability to dissipate the extra heat. When you exercise, almost 80 percent of the energy that is used to drive your muscles is lost as heat. That means that the harder you exercise, the more heat you produce. But heat stroke is more likely to be caused by inability to get rid of heat than by producing too much heat. Stimulants such as amphetamines, caffeine or ecstacy increase the likelihood of heatstroke.
Those most likely to suffer heat stroke are those who have arteriosclerosis, are overweight or are in poor shape. An athlete or exerciser who passes out from overheating should be immersed in cold water immediately to prevent brain and multiple organ damage. However, a heart attack can also cause a person to pass out and this should not be treated with cold water immersion.
If you exercise in the heat and start to feel dizzy, stop exercising because your temperature could be rising too high. When your temperature starts to rise, your muscles start to burn. As your temperature rises further, you become short of breath and the air you breathe feels like it is coming from a hot furnace. Stop exercising and cool off because if your temperature continues to rise, you will develop brain symptoms such as headache, blurred vision, and ringing in your ears. If you press on further, you can pass out and die. More