Heat Stroke: Symptoms, Causes, Treatment

It differs from heat exhaustion, which typically causes sweating, weakness and thirst without severe neurological dysfunction. Profuse sweating can occur in heatstroke; dry skin is not required.

Related reading: Dehydration and symptoms of fluid loss.

Confusion, behavioral change, poor coordination, seizures or unconsciousness with marked overheating are warning signs. Fast pulse, headache and nausea may accompany them.

Extreme environmental heat or strenuous activity can overwhelm cooling, particularly with humidity, inadequate ventilation, dehydration or medicines affecting heat tolerance.

Infants, older adults, people with chronic illness and workers or athletes in heat face increased risk. Humidity, limited acclimatization, some medicines and recreational drugs add risk.

Emergency assessment considers exposure, temperature and neurological status, with tests for kidney, liver, muscle, electrolyte and clotting injury. Cooling should not await laboratory results.

Call emergency services, move the person to a safe cool place, remove excess clothing, wet the skin with cool water and fan. Do not give drinks to someone with impaired consciousness.

Brain injury, kidney or liver failure, muscle breakdown, clotting disturbances or death may follow. Rapid cooling and medical care reduce injury even if temperature has begun falling.

Plan shade, rest, suitable fluids and gradual heat acclimatization; check vulnerable people. Never leave a child or dependent person in a parked vehicle.