Emergency First Aid for Heatstroke

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Heatstroke is a condition that occurs when the body fails to control its own temperature and body temperature keeps rising. Symptoms of heatstroke include mental changes (such as confusion, delirium, or unconsciousness) and skin that is red, hot, and dry, even under the armpits. Heatstroke can be deadly. It needs emergency medical treatment.

Signs of rapidly progressing heatstroke include:

  • Unconsciousness for longer than a few seconds.
  • Convulsion (seizure).
  • Signs of moderate to severe difficulty breathing.
  • A rectal temperature over 104 F (40 C) after exposure to a hot environment.
  • Confusion, severe restlessness, or anxiety.
  • Fast heart rate.
  • Skin that may be red, hot, and dry, even in the armpits. (Sweating has stopped.)
  • Severe vomiting and diarrhea.

Giving emergency first aid

Heatstroke is a medical emergency. Even with immediate treatment, it can be life-threatening or result in serious, long-term complications. After calling 911 or other emergency medical services, follow these first aid steps.

  • Cool the body.
    • Move the person into a cool place, out of direct sunlight.
    • Remove the person's unnecessary clothing, and place the person on their side to expose as much skin surface to the air as possible.
    • Cool the person's entire body in a cold water or ice bath or by sponging or spraying cold water, and fan the person to help lower the person's body temperature.
    • Apply ice packs over as much of the body as you can.
  • Check the person's rectal temperature.

    Try to reduce it to 102 °F (39 °C) or lower as soon as possible. The longer the body is at a high temperature, the more serious the illness and the more likely it is that complications will develop. Temperatures taken by mouth or in the ear are not accurate in this emergency situation

  • Watch for signs of rapidly progressing heatstroke.

    These include seizure, unconsciousness for longer than a few seconds, and moderate to severe difficulty breathing.

  • Start CPR if needed.

    If the person is unconscious or does not respond to your voice or touch, be ready to start CPR.

  • Give the person fluids for hydration.

    If the person is awake and alert enough to swallow, give them plenty of cool water to drink. You may have to help. Make sure the person is sitting up enough so that they don't choke. Most people with heatstroke have an altered level of consciousness and cannot safely be given fluids to drink.

Do not give aspirin or acetaminophen to reduce a high body temperature that can occur with heatstroke. These medicines may cause problems because of the body's response to heatstroke.

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Current as of: July 10, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

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