Menu Healthy Lifestyle Diseases & Conditions First Aid Symptoms Tests & Procedures Videos Definitions FAQs Heat exhaustion: First aidUpdated: 2022-04-15Heat exhaustion is one of the heat-related syndromes. These syndromes range in severity and seriousness from mild to potentially life-threatening. Other types of heat-related illnesses include heat rash, heat cramps, heat syncope and heatstroke. Heat exhaustion can occur when your body loses too much water or salt — usually as a result of excessive sweating or dehydration. It can begin suddenly or happen over time, usually after working, exercising or playing in the heat. Heat exhaustion signs and symptoms include: Cool, moist skin with goose bumps when in the heat Heavy sweating Faintness Dizziness Fatigue Weak, rapid pulse Low blood pressure upon standing Muscle cramps Nausea or vomiting Headache Extreme thirst Mild confusion Decreased urine output If you suspect heat exhaustion Untreated, heat exhaustion can lead to heatstroke, which is a life-threatening condition. If you suspect heat exhaustion, take these steps immediately: Move the person out of the heat and into a shady or air-conditioned place. Lay the person down and elevate the legs and feet slightly. Remove tight or heavy clothing. Have the person sip chilled water, a decaffeinated sports drink containing electrolytes or other nonalcoholic beverage without caffeine. Cool the person by spraying or sponging with cool water and fanning. Monitor the person carefully. Contact a health care provider if signs or symptoms worsen or if the person doesn't improve after taking first-aid measures. Call 911 or your local emergency number if the person's condition gets worse, especially if he or she experiences: Fainting Agitation Confusion Seizures Inability to drink Core body temperature — measured by rectal thermometer — of 104 F (40 C) (heatstroke) © 1998-2022 Mayo Foundation for Medical Education and Research(MFMER). All rights reserved. Terms of Use