The injury because of hot temperature happen because of the body system can not overcome external temperature. Mild state syndrome happen when there is movement activity and the severe one happen when do not act movement.  Core body temperature more than 40⁰ C (104⁰ F) can disturb Central Nervous System and anhydrosis.

Classic heat stroke, this will happen on person who do not have acclimatization (acclimatization on hot temperature need 3-5 days) yet and get hot temperature application for several days. The risk factors that related to this heat stroke are: chronic disease, old age, damp, obesity, chronic cardiovascular disease, poorness, alcoholic, dehydration, and using sedative. Heat stroke on old age patient who lying down for long time happen because cardiovascular system can not accommodate to hot temperature. 

Exercise induced heat stroke, shown on person who doing exercise at damp and high temperature, usually presented on young people (athlete, military cadre, n labourer) . About 4.000 people/year in USA died because heat stroke. The patient will be easier to get DIC, lactic acidosis, and rhabdomyolisis.

The treatment is refrigeration quickly, choosen with using fan. Using ice compress or soak in cold water are also effective, but when trembling happen will lessen effectiveness. It is often needed infusion with NaCl 0,9% 20 cc/kg for 4 hours first. Refrigeration quickly have to be discontinued when gotten temperature 38,9⁰ C (102⁰ F).
Mannitol is given early for myoglobinuria condition. Prognosis is bad if the temperature reach 42,2⁰ C (108⁰ F) or more, coma more than 2 hours, shock and hyperkalemia. Mortality rate are about 10%.   

The best way prevent heat stroke are often take a rest and drink much water. Requirement drink water in desert temperature  49⁰ C (120⁰ F) is 2 litre/hours. (doc b3ty)