Heat stroke
Heat stroke or heatstroke, also known as sun-stroke, is a severe heat illness that results in a body temperature greater than 40.0 °C (104.0 °F), along with red skin, headache, dizziness, and confusion. Sweating is generally present in exertional heatstroke, but not in classic heatstroke. The start of heat stroke can be sudden or gradual. Heatstroke is a life-threatening condition due to the potential for multi-organ dysfunction, with typical complications including seizures, rhabdomyolysis, or kidney failure.
| Heat stroke | |
|---|---|
| Other names | Sun-stroke, siriasis |
| Person being cooled with water spray, one of the treatments of heat stroke, in Iraq in 1943 | |
| Specialty | Emergency medicine |
| Symptoms | High body temperature, red, dry or damp skin, headache, dizziness, confusion, nausea |
| Complications | Seizures, rhabdomyolysis, kidney failure |
| Types | Classic, exertional |
| Causes | High external temperatures, physical exertion |
| Risk factors | Extremes of age, heat waves, high humidity, certain drugs, heart disease, skin disorders |
| Diagnostic method | Based on symptoms |
| Differential diagnosis | Neuroleptic malignant syndrome, malaria, meningitis |
| Treatment | Rapid cooling, supportive care |
| Prognosis | Risk of death <5% (exercise induced), up to 65% (non-exercise induced) |
| Deaths | > 600 per year (US) |
Heat stroke occurs because of high external temperatures and/or physical exertion. It usually occurs under preventable prolonged exposure to extreme environmental or exertional heat. However, certain health conditions can increase the risk of heat stroke, and patients, especially children, with certain genetic predispositions are vulnerable to heatstroke under relatively mild conditions.
Preventive measures include drinking sufficient fluids and avoiding excessive heat. Treatment is by rapid physical cooling of the body and supportive care. Recommended methods include spraying the person with water and using a fan, putting the person in ice water, or giving cold intravenous fluids. Adding ice packs around a person is reasonable but does not by itself achieve the fastest possible cooling.
Heat stroke results in more than 600 deaths a year in the United States. Rates increased between 1995 and 2015. Purely exercise-induced heat stroke, though a medical emergency, tends to be self-limiting (the patient stops exercising from cramp or exhaustion) and fewer than 5% of cases are fatal. Non-exertional heatstroke is a much greater danger: even the healthiest person, if left in a heatstroke-inducing environment without medical attention, will continue to deteriorate to the point of death, and 65% of the most severe cases are fatal even with treatment.