Last updated on: August 21st, 2021

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Heatstroke and sunstroke

Clinicals - History


Heatstroke (HS), also known as sunstroke, is a medical emergency characterized by increased body temperatures and central nervous system (CNS) dysfunction. Severe cases can result in disseminated intravascular coagulopathy (DIC), multiple organ dysfunction syndrome (MODS), and death.

Classical heatstroke: exposure to heat

HS occurs more frequently during the summer, especially if there are heatwaves. This is due to prolonged exposure to elevated temperatures. Increased humidity may contribute, by reducing the body's ability to dissipate heat by sweating.

Exertion heatstroke: exertion

Exertional heat stroke (EHS) can occur in athletes, laborers, or other persons exerting themselves for a longer period of time, or at a greater intensity than is safe. This risk is increased in warmer environments.

Altered mental status

Confusion, disorientation, strange behavior, or loss of consciousness are classic presenting symptoms. This is because of electrolyte imbalances due to water and sodium loss.


Headache is a common presenting symptom. This occurs due to electrolyte and fluid imbalances.


Severe HS can lead to seizures and rarely, status epilepticus. This is believed to be due to cytokine release, and other neuronal cellular changes induced by hyperthermia.

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