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What is heatstroke?

Heatstroke is when your body severely overheats. Heatstroke happens when you do intense physical activity in hot conditions without drinking enough liquids. Normally, the body has a cooling system that is controlled by the brain. The cooling system adjusts to hot conditions and lowers your body temperature by producing sweat. With heatstroke, the body's cooling system is not working well and results in an increased body temperature.

What increases my risk of heatstroke?

  • Age: Older adults and young children have a hard time adjusting quickly to high temperatures and humid conditions.
  • Obesity: You may not be able to regulate your body temperature if you are obese. This can cause your body to overheat.
  • Medicines: Certain medicines used for treating pain, allergies, depression, heart problems, or tumors can cause dehydration or keep your body from cooling off as it should.
  • Illegal drugs and alcohol: Illegal drugs may damage your body's ability to cool itself. Alcohol can cause dehydration and lead to heatstroke.

What are the signs and symptoms of heatstroke?

  • Your temperature is 104°F (40°C) or higher.
  • Your skin may be red and dry or clammy.
  • You have a headache, nausea, or vomiting.
  • You have muscle cramps.
  • You breathe fast or feel like your heart is beating faster than normal.
  • You feel faint, dizzy, weak, or tired.
  • You may have a prickling feeling in your arms or legs.
  • You may have a seizure or faint.

How is heatstroke diagnosed?

Your healthcare provider will take your temperature. You may also need any of the following tests:

  • Blood and urine tests: Samples of your blood and urine are collected. These are sent to a lab for tests to check the levels of salts and minerals.
  • Blood gases: This is also called an arterial blood gas, or ABG. Blood is taken from an artery (blood vessel) in your wrist, arm, or groin. Your blood is tested for the amount of oxygen and carbon dioxide in it.
  • ECG: This is also called an EKG. This test records a short period of electrical activity in your heart. An ECG is done to check for damage or problems in your heart.

What first aid can I do for heatstroke?

  • Move to an air-conditioned location or a cool, shady area and lie down. Raise your legs above the level of your heart.
  • Drink cold liquid, such as water or a sports drink.
  • Mist yourself with cold water or pour cool water on your head, neck, and clothes.
  • Apply ice packs on your neck, armpits, and groin.
  • Loosen or remove as many clothes as possible.
  • Have someone call 911 immediately for medical assistance.

How is heatstroke treated?

  • Cooling materials: Different types of cooling materials may be used to quickly decrease your body temperature, such as ice-soaked blankets.
  • IV fluids: These may be given to increase your fluid volume to treat dehydration.
  • Medicines:
    • Anticonvulsant medicine: This medicine is given to control seizures. Take this medicine exactly as directed.
    • Alkalinizing agents: These medicines, such as potassium and sodium bicarbonate, decrease the amount of acid in your blood and urine. This helps prevent organ damage.
    • Vasopressors: These medicines make your blood vessels contract and raise your blood pressure.
  • Respiratory support:
    • You may need extra oxygen if your blood oxygen level is lower than it should be. You may get oxygen through a mask placed over your nose and mouth or through small tubes placed in your nostrils. Ask your healthcare provider before you take off the mask or oxygen tubing.
    • A ventilator is a machine that gives you oxygen and breathes for you when you cannot breathe well on your own. An endotracheal (ET) tube is put into your mouth or nose and attached to the ventilator. You may need a trach if an ET tube cannot be placed. A trach is a tube put through an incision and into your windpipe.

What are the risks of heatstroke?

Your condition may worsen if you are cooled down too rapidly or receive too much fluid. Without treatment, you may pass out or have a seizure. As your body temperature rises, your brain and other organs may be damaged. Heatstroke can lead to severe dehydration and organ failure. Organ failure is when your heart, liver, or kidneys cannot work properly due to lack of oxygen. Heatstroke is a serious, life-threatening condition.

How can I prevent heatstroke?

  • Wear lightweight, loose, and light-colored clothing.
  • Protect your head and neck with a hat or umbrella when you are outdoors.
  • Drink lots of water or sports drinks. Avoid alcohol.
  • Eat salty foods, such as salted crackers and salted pretzels.
  • Limit your activities during the hottest time of the day. This is usually late morning through early afternoon.
  • Use air conditioners or fans and have enough proper ventilation. If there is no air conditioning available, keep your windows open so air can circulate.
  • Never leave children alone inside cars, especially during hot weather.

When should I contact my healthcare provider?

  • Your skin is red and dry.
  • You have muscle cramps or twitching.
  • You have nausea and vomiting.
  • You have numbness or prickling feeling in your arms or legs.
  • You have questions or concerns about your condition or care.

When should I seek immediate care or call 911?

  • Your temperature is 104°F (40°C) or higher.
  • You cannot stop vomiting.
  • You feel faint, dizzy, weak, or tired.
  • You are confused or cannot think clearly.
  • You cannot move your arms and legs.
  • You breathe fast or feel like your heart is beating faster than normal.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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