Heat stroke is a condition where body surfers from both increased body temperature (hyperthermia) and shock due to water loss (dehydration). When body exposed to any heat (not only from the sun) that intend to increase body temperature above normal (hyperthermia), body mobilizes certain thermo-regulatory mechanisms that will keep the body temperature in normal range. The most important mechanism for preventing hyperthermia is sweating. Sweating by itself does not prevent hyperthermia but evaporation of the sweat on body's surface decreases the body's temperature and neutralizes temperature increase. This means that sweating won't be efficient if there is no evaporation. Evaporation can be disturbed if air's humidity is too big (no ventilation) or person wears improper clothes. Sweating spends body's water so it requires water intake. If water intake is not enough body will loss to much water and go into hypovolemic shock. Sweating will also stop and body temperature will increase (hyperthermia). This condition, dehydration plus hyperthermia is called heat stroke.
This means that heat stroke can happen whenever there is heat exposure, high air humidity, intensive physical efforts and reduced water intake.
Recovery depends from the heat stroke severity.
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