Heatstroke

High urgency
-Moderately severe

Heatstroke occurs when the body loses its ability to regulate body temperature and the temperature persistently exceeds 104°F (40°C).

The exact cause is unknown, although a genetic predisposition has been suggested. Factors that contribute to this condition include
a) Increased heat production (exercise, fever, medications, thyroid disorders),
b) decreased heat loss (high environmental heat and humidity, dehydration, medications, decreased sweating),
c) dysfunction of temperature regulation (in people with disabilities).

Symptoms of prolonged high fever include flushing, sweating/dry skin, rapid heartbeat, dizziness, headache, delirium, confusion, and seizures. Severe cases may result in death.

Diagnosis is made clinically by interview and physical examination. Additional tests, including blood tests and imaging, may be used to rule out infection.

The goal of treatment is to cool the body (in a cool environment, without clothing, using cold water-soaked compresses or towels, etc.). It is advisable to avoid prolonged exposure to the sun, avoid exercise during the peak hours of the heat, and ensure proper hydration.

Bibliographic references
  1. C Crawford Mechem. Severe nonexertional hyperthermia (classic heat stroke) in adults. UpToDate. Jun 10, 2015.
  2. Lipman GS, Eifling KP, Ellis MA, et al. Wilderness Medical Society practice guidelines for the prevention and treatment of heat-related illness. Wilderness Environ Med 2013; 24:351.
  3. Druyan A, Janovich R, Heled Y. Misdiagnosis of exertional heat stroke and improper medical treatment. Mil Med 2011; 176:1278.
  4. Francis G O'Connor, Douglas J Casa. Exertional heat illness in adolescents and adults: Epidemiology, thermoregulation, risk factors, and diagnosis. UpToDate. Aug 31, 2015.
  5. Flores-Valderas J, Pérez-romero T, Palomo de los Reyes, MJ. Urgencias pòr calor. Manual de protocolos y actuación en urgencias. Hospital Virgen de la Salud, Complejo Hospitalario de Toledo. Tercera edición. 2010: 1393-1397.
Author
Dr. Sara Vitoria
Copyright
© TeckelMedical 2026

Symptoms

    High fever of 40ºC/104ºF or above


    Dry skin


    Temperature > 41ºC / 105.8ºF


    Widespread muscle pain


    low level of consciousness

Pre-hospital care recommendations

Take over-the-counter pain relievers or anti-inflammatories.
Apply cold compresses 3 times a day for 20 minutes to reduce the symptoms.
Maintain a fluid intake of 6 - 8 cups per day.
Relative rest, rest until symptoms subside.