Overview
Heat stroke is when body temperature rises over 103°F with confusion; it's life-threatening.
Symptoms
Common signs:
- Heavy sweating, weakness, or dizziness in the heat
- Feeling sick after being in the heat
Less common
- Nausea
- Headache
- Muscle cramps
Look up a symptom: Can't stand the heat, or sweating a lot · Dizziness · Feeling sick after being in the heat · Headache · Muscle cramp or charley horse · Nausea
When to get medical care
Call 911Confusion, passing out, hot skin with no sweating, or temperature over 103°F: call 911 and cool the person.
Get care todayVomiting, or symptoms not better in an hour.
See a doctor soonHeat cramps or tiredness that come back each time you're in the heat.
Causes
Heat, exercise, dehydration.
Who is more likely to get it
- Older adults
- Outdoor workers
- Athletes
Possible complications
Diagnosis
Diagnosis by signs.
Treatment
Cool off right away.
Self-care
- Move to shade or AC
- Loosen clothes
- Use cool, wet cloths or a cool bath
- Sip water or a sports drink
Prevention
To prevent it:
- Drink water
- Rest in shade
- Avoid midday heat
Which doctor treats this
- Urgent care or the ER can treat it first. For minor problems, your primary care provider can help.
Back to school, work, or sports
- Recovery time varies. Ask your care team when you can drive, lift, work, and exercise.
Outlook
Recovers with fast cooling.
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Sources
Last updated 2026-11-12.