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Heat Exhaustion: Care Instructions

Your Care Instructions

Heat exhaustion occurs when you are hot, sweat a lot, and do not drink enough to replace the lost fluids. Heat exhaustion is not the same as heatstroke, which is much more serious. Heatstroke can lead to problems with many different organs and can be life-threatening.

After medical care for heat exhaustion, you will need to limit your activities and take good care of your body while it recovers.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

How can you care for yourself at home?

  • Reduce your activities, and get plenty of rest. Your doctor will give you instructions on when you can resume your normal schedule.
  • Stay in a cool room for at least the next 24 hours.
  • Drink rehydration drinks, juices, and water to replace fluids. Drinks such as sports drinks that contain electrolytes work best, because they have salt and minerals. You need salt and minerals as well as water. If you have kidney, heart, or liver disease and have to limit fluids or salt, talk with your doctor before you increase your fluid or salt intake.
  • Avoid drinks that have alcohol.

To prevent heat exhaustion

  • Drink plenty of fluids. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase the amount of fluids you drink.
  • Drink plenty of water before, during, and after you are active. This is very important when it is hot out and when you do intense exercise.
  • During hot weather, wear light-coloured clothing that fits loosely and a hat with a brim to reflect the sun.
  • Limit or avoid strenuous activity during hot or humid weather, especially during the hottest part of the day (11 a.m. to 3 p.m.). Heat exhaustion and heatstroke usually develop when you are working or exercising in hot weather. Humidity makes hot weather even more dangerous.
  • Cars can get very hot inside. Open the windows or turn on the air conditioning before you get in and close the doors.
  • Try to stay cool during hot weather. If your home is not air-conditioned, seek an air-conditioned place. That could be in the library, a neighbourhood café, or a friend's home. Spray yourself with a cool mist. Take a cool shower, bath, or sponge bath.
  • Be aware that some medicines, such as major tranquilizers, can raise the risk of heat exhaustion. Ask your doctor whether any medicine you take raises your chance of getting heat exhaustion.

When should you call for help?

Call 911 anytime you think you may need emergency care. For example, call if:

  • You feel very hot and:
    • You have a seizure.
    • You feel confused.
    • Your skin is red, hot, and dry.
    • You passed out (lost consciousness).

Call your doctor or nurse advice line now or seek immediate medical care if:

  • You cannot keep fluids down.
  • After returning to your normal activities, you have symptoms of heat exhaustion, such as sweating a lot, fatigue, dizziness, or nausea.

Watch closely for changes in your health, and be sure to contact your doctor or nurse advice line if:

  • You do not get better as expected.

Where can you learn more?

Go to

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Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.