Definition of heat stress?

heat stress disorder

a group of conditions due to overexposure to or overexertion in excess environmental temperature.

It includes heat cramps, which are non-emergent and treated by salt replacement; heat exhaustion, which is more serious, treated with fluid and salt replacement; and heatstroke, a condition most commonly affecting extremes of age, especially the elderly, accompanied by convulsions, delusions, or coma and treated with cooling the body and replacement of fluids and salts.

heatstroke

a severe and often fatal illness produced by exposure to excessively high temperatures, especially when accompanied by marked exertion.

It can manifest by elevated body temperature, lack of sweating, hot dry skin, and neurologic symptoms; unconsciousness, paralysis, headache, vertigo, confusion. in severe cases very high fever, vascular collapse, and coma develop.

Synonym: heat apoplexy, heat hyperpyrexia, malignant hyperpyrexia, thermic fever.