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Heat Exhaustion

What is heat exhaustion?

Heat exhaustion is when your body overheats. Heat exhaustion 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 heat exhaustion, the body's cooling system is not working well and results in an increased body temperature.

What increases my risk of heat exhaustion?

  • 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 heat exhaustion.

What are the signs and symptoms of heat exhaustion?

  • You may have heavy sweating.

  • You may feel faint, dizzy, weak, or tired.

  • You may have a headache.

  • You may breathe fast or feel like your heart is beating faster than normal.

  • You may have muscle cramps.

  • You may have nausea or vomiting.

How is heat exhaustion diagnosed?

Your caregiver 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.

  • Telemetry is continuous monitoring of your heart rhythm. Sticky pads placed on your skin connect to an EKG machine that records your heart rhythm.

What first aid can I do for heat exhaustion?

  • 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.

  • Loosen or remove as many clothes as possible.

  • If you do not feel better in 1 hour, go to the emergency department.

How is heat exhaustion 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 prevent or treat dehydration.

  • Oral rehydrating solutions: Caregivers may give you oral rehydration solution (ORS) to drink. An ORS has the right amounts of water, salts, and sugar your body needs to replace body fluids. This may help prevent dehydration.

What are the risks of heat exhaustion?

Your condition may worsen if you are cooled down too rapidly or receive too much fluid. Without treatment, you may become severely dehydrated and develop heatstroke. If this happens, you may pass out or have a seizure. Your blood, kidneys, lungs, liver, heart, or brain may not work as they should. This can be life-threatening.

How can I prevent heat exhaustion?

When you exercise or are somewhere with a high temperature and humidity:

  • 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.

When should I contact my caregiver?

Contact your caregiver if:

  • Your signs and symptoms do not improve with treatment.

  • 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?

Seek care immediately or call 911 if:

  • You cannot stop vomiting.

  • You are confused or cannot think clearly.

  • You cannot move your arms and legs.

  • You have trouble breathing.

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 caregivers 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.

© 2015 Truven Health Analytics Inc. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or Truven Health Analytics.