Symptoms of Heat-Related Illnesses

Key points

  • Heat-related illnesses are preventable.
  • Learn the symptoms and what to do if you or a loved one shows signs of having a heat-related illness.

Signs and symptoms

Man wiping sweat off face while standing in the sun
Know the signs and symptoms of heat-related illnesses.

Heat stroke

What to look for
  • High body temperature (103°F or higher)
  • Hot, red, dry, or damp skin
  • Fast, strong pulse
  • Headache
  • Dizziness
  • Nausea
  • Confusion
  • Losing consciousness (passing out)
What to do
  • Call 911 right away-heat stroke is a medical emergency
  • Move the person to a cooler place
  • Help lower the person's temperature with cool cloths or a cool bath
  • Do not give the person anything to drink

Heat exhaustion

What to look for
  • Heavy sweating
  • Cold, pale, and clammy skin
  • Fast, weak pulse
  • Nausea or vomiting
  • Muscle cramps
  • Tiredness or weakness
  • Dizziness
  • Headache
  • Fainting (passing out)
What to do
  • Move to a cool place
  • Loosen your clothes
  • Put cool, wet cloths on your body or take a cool bath
  • Sip water
Get medical help right away if:
  • You are throwing up
  • Your symptoms get worse
  • Your symptoms last longer than 1 hour

Heat cramps

What to look for
  • Heavy sweating during intense exercise
  • Muscle pain or spasms
What to do
  • Stop physical activity and move to a cool place
  • Drink water or a sports drink
  • Wait for cramps to go away before you do any more physical activity
Get medical help right away if:
  • Cramps last longer than 1 hour
  • You’re on a low-sodium diet
  • You have heart problems


What to look for
  • Painful, red, and warm skin
  • Blisters on the skin
What to do
  • Stay out of the sun until your sunburn heals
  • Put cool cloths on sunburned areas or take a cool bath
  • Put moisturizing lotion on sunburned areas
  • Do not break blisters

Heat rash

What to look for
  • Red clusters of small blisters that look like pimples on the skin (usually on the neck, chest, groin, or in elbow creases)
What to do
  • Stay in a cool, dry place
  • Keep the rash dry
  • Use powder (like baby powder) to soothe the rash

Printable infographic

Text demonstrating what to look for and what to do for various heat-related illnesses, including heat stroke, heat exhaustion, heat cramps, sunburn, and heat rash.
Learn signs and symptoms of heat-related illnesses.

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