Heart Risks

Heat Exhaustion and Heatstroke: What You Should Know

What is heat exhaustion?

Heat exhaustion happens when your body gets too hot. It can be caused by exercise or hot weather. You may feel weak, dizzy, or worried. You also may have a headache or a fast heartbeat. You may get dehydrated and have very little urine.

What should I do if I think I have heat exhaustion?

Get out of the heat quickly. Rest in a cool, shady place. Drink plenty of water or other fluids. Do NOT drink alcohol. Alcohol can make heat exhaustion worse. If you do not feel better within 30 minutes, you should see your doctor. If heat exhaustion is not treated, you can get heatstroke.

What is heatstroke?

Heatstroke is much more serious than heat exhaustion and can kill you. People with heatstroke may seem confused. They may have seizures or go into a coma. Most people with heatstroke also have a fever. Heatstroke can happen when your body gets too hot, or it can develop from heat exhaustion.

What should I do if I think someone has heatstroke?

Take him or her to a cool, shady place quickly. Call an ambulance (911). Removing the person's unnecessary clothing. Bathe or spray the person's skin with cool water. Try to fan warm air over the person while wetting the skin with lukewarm water. the evaporation of the water will speed cooling.

How can I keep from getting heat exhaustion and heatstroke?

Do not exercise outside when it is hot and humid. If you have traveled to a place that is hotter than where you live, do not exercise for at least a week. In hot weather, wear cool, light clothing and drink plenty of nonalcoholic fluids. If a heat wave happens, stay in an air-conditioned place. Get medical help immediately if you think you might have heat exhaustion or heatstroke.

How do medicines affect your response to heat?

Some medicines can put you in danger of heatstroke:

Allergy medicines (antihistamines)
Cough and cold medicines (antihistamines, decongestants) - Including pseudoephedrine (one brand: Sudafed)
Blood pressure and heart medicines
Beta blockers
Calcium channel blockers
Diuretics ("water pills")
Diet pills
Irritable bladder and irritable bowel medicines (anticholinergics)
Laxatives
Mental health medicines
Benzodiazepines
alprazolam (Xanax)
chlordiazepoxide (one brand: Librium)
clonazepam (one brand: Klonopin)
diazepam (one brand: Valium)
Medicines for schizophrenia
Tricyclic antidepressants
amitriptyline
desipramine
doxepin
imipramine
Seizure medicines (anticonvulsants)

We can tell you if your medicine is on this list.

What should I do after having heat exhaustion or heatstroke?

Having heat exhaustion or heatstroke makes you more sensitive to hot conditions for about a week afterwards. Be especially careful not to exercise too hard, and avoid hot weather. Ask us when it is safe to return to your normal activities.