Signs of heat exhaustion and heat stroke
Paleness, heavy sweating, dizziness and nausea in the heat sound like heat exhaustion: get the person into shade or air conditioning, loosen clothing, apply cool wet cloths and offer sips of water if they are alert. Confusion, fainting, hot skin or a seizure point to heat stroke: call your local emergency number, 911 in the US, and cool them with water while you wait.
At an outdoor festival your friend is pale, sweating hard, dizzy and queasy.
Why it matters: On a hot day at a fair, a game or a garden, knowing which signs mean call now can save a life.
In an emergency, call your local emergency number, 911 in the US, first. Reading a page is not training: take a certified class and practice on a manikin.
Steps
- On hot days, drink water regularly, take shade breaks and watch the people with you.
- For heavy sweating, pale clammy skin, dizziness, cramps, headache or nausea, move the person to shade or air conditioning.
- Loosen tight clothing and apply cool, wet cloths or a cool shower.
- Offer sips of water if they are fully alert and not vomiting.
- Book urgent care or call for advice if vomiting starts, symptoms climb, or an hour of rest and cooling has not helped.
- For confusion, slurred speech, fainting, hot skin or a seizure, call your local emergency number, 911 in the US.
- While help is on the way, soak her skin with cold water, press cold packs into the armpits, neck and groin, and keep air moving over her.
- Take a certified class to practice first aid for heat and other emergencies.
Stop and call a professional if
- the person is confused, faints, has a seizure or has hot skin: call your local emergency number, 911 in the US, now
- symptoms climb or an hour of rest and cooling has not helped
Common mistakes
- Giving drinks to someone who is confused or not fully awake.
- Assuming someone still sweating cannot have heat stroke.
- Waiting to see whether confusion clears on its own.
Teach this to someone
A one page sheet for showing a friend, a teenager or a parent: what to say, what to show, and one question to check it landed.
Teach: Signs of heat exhaustion and heat stroke
What to say
Paleness, heavy sweating, dizziness and nausea in the heat sound like heat exhaustion: get the person into shade or air conditioning, loosen clothing, apply cool wet cloths and offer sips of water if they are alert. Confusion, fainting, hot skin or a seizure point to heat stroke: call your local emergency number, 911 in the US, and cool them with water while you wait.
What to show
- On hot days, drink water regularly, take shade breaks and watch the people with you.
- For heavy sweating, pale clammy skin, dizziness, cramps, headache or nausea, move the person to shade or air conditioning.
- Loosen tight clothing and apply cool, wet cloths or a cool shower.
- Offer sips of water if they are fully alert and not vomiting.
- Book urgent care or call for advice if vomiting starts, symptoms climb, or an hour of rest and cooling has not helped.
- For confusion, slurred speech, fainting, hot skin or a seizure, call your local emergency number, 911 in the US.
- While help is on the way, soak her skin with cold water, press cold packs into the armpits, neck and groin, and keep air moving over her.
- Take a certified class to practice first aid for heat and other emergencies.
Where it stops
Stop and call a professional if the person is confused, faints, has a seizure or has hot skin: call your local emergency number, 911 in the US, now.
Check question
Which sign means heat stroke rather than heat exhaustion?
Answer: Confusion or fainting. Changes in thinking or consciousness mean an emergency.
Your checklist
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Quick quiz
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Related skills
Sources
- US national first aid guidelines for lay responders, 2025. Reviewed September 28, 2026.
Written in our own words from the sources above. It is general information, not advice for your situation; where a professional, your doctor or your lease says something different, follow them.
Last reviewed . First published .