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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medically reviewed by WellAlly Editorial TeamLast reviewed October 19, 2026Editorial policy
First Aid18 min read

Heat Exhaustion First Aid

Published: October 19, 2026Updated: October 19, 2026

Heat exhaustion occurs when the body overheats due to prolonged exposure to high temperatures and dehydration. Recognizing the signs—such as heavy sweating, dizziness, and nausea—and acting quickly is critical to prevent progression to life-threatening heat stroke. Prompt cooling and hydration are the cornerstones of effective first-aid management.

Quick Summary

Move the person to a cool, shaded area, loosen tight clothing, apply cool damp cloths to the skin, and provide small sips of water or electrolyte fluids.

Important Medical Disclaimer

This guide is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with qualified healthcare providers for medical concerns.

Step-by-Step Guide

1

Move to a Cooler Environment

Immediately get the person out of direct sunlight and into an air-conditioned room or a well-ventilated, shaded area. Have them sit or lie down to minimize physical exertion and metabolic heat production. Ensure airflow around the person by opening windows or turning on a fan.

2

Loosen and Remove Excess Clothing

Remove heavy, tight, or unnecessary layers of clothing such as jackets, hats, socks, and shoes. Exposing more skin allows trapped heat to radiate away from the body and enhances the effectiveness of external cooling measures. Ensure the person remains comfortable and covered with light fabric if needed.

3

Actively Cool the Body

Apply cool, damp cloths or ice packs wrapped in towels to areas with high blood flow, such as the neck, armpits, and groin. You can also mist the person's skin with cool water while gently fanning them to facilitate evaporative heat loss. Avoid placing bare ice directly on the skin.

Important: Do not submerge an alert heat exhaustion patient in an ice bath without medical supervision, as extreme cold can trigger intense shivering, which paradoxically raises core body temperature.

4

Sip Cool Fluids Slowly

Provide cool water, diluted sports drinks, or commercial oral rehydration solutions to replace lost fluids and electrolytes. Encourage slow, steady sips rather than gulping to prevent gastrointestinal upset. Aim for roughly half a glass of fluid every 15 minutes if tolerated.

Important: Do not give liquids containing caffeine or alcohol, and never force fluids if the person is vomiting, severely nauseated, or showing signs of altered consciousness.

5

Rest with Legs Elevated

Have the person lie flat on their back and elevate their feet 8 to 12 inches using pillows or folded blankets. This position promotes venous blood return to the heart and brain, helping alleviate dizziness and orthostatic hypotension. Keep them resting quietly until their body temperature normalizes.

6

Monitor Closely for Heat Stroke

Stay with the person continuously and observe their alertness, breathing, and skin temperature. Most individuals with heat exhaustion begin to recover within 30 to 45 minutes of resting and cooling. If symptoms do not improve or begin to worsen, escalate to emergency medical care.

Important: Call 911 immediately if the person develops a core temperature of 104°F (40°C) or higher, confusion, slurred speech, seizures, or loss of consciousness, as these indicate heat stroke.

Frequently Asked Questions

What is the difference between heat exhaustion and heat stroke?
Heat exhaustion causes heavy sweating, cool clammy skin, nausea, and weakness while mental function remains intact. Heat stroke is a medical emergency marked by altered mental status (confusion, delirium, unconsciousness), a core temperature of 104°F (40°C) or higher, and potentially hot, red, dry skin.
How long does it take to recover from heat exhaustion?
Most people notice significant relief within 30 to 60 minutes after cooling down and rehydrating. However, complete physiological recovery typically requires 24 to 48 hours of rest, and individuals should avoid strenuous physical activity and sun exposure for several days.
Can heat exhaustion happen indoors?
Yes. Heat exhaustion frequently occurs indoors in poorly ventilated spaces, top-floor apartments, or rooms without air conditioning during periods of high ambient temperature and humidity.
When is it necessary to go to the emergency room?
Seek emergency medical care if the person cannot keep fluids down due to persistent vomiting, becomes disoriented or unresponsive, experiences fainting, or fails to improve after 30 minutes of active cooling.
  1. 1
    Centers for Disease Control and Prevention (CDC)Source
  2. 2
    Mayo ClinicSource
  3. 3
    National Health Service (NHS)Source

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed October 19, 2026. · Read our editorial policy