Health Library

What Is Heat Illness?

In very hot weather, high humidity, and other conditions, body heat can build to dangerous levels. This can cause heat illness, such as heat cramps, heat exhaustion, or heatstroke. Heat exhaustion starts slowly, but if it’s not quickly treated it can progress to heatstroke. In heatstroke, a person’s temperature reaches 105°F (40.5°C) or higher. Heatstroke needs emergency medical care right away and can be life-threatening.

What Are the Signs & Symptoms of Heat Illness?

Of heat exhaustion:

• increased thirst
• weakness and extreme tiredness
• fainting
• muscle cramps
• nausea and vomiting
• irritability
• headache
• increased sweating
• cool, clammy skin
• body temperature rises, but to less than 105°F (40.5°C)

Of heatstroke:

• severe headache
• weakness, dizziness
• confusion
• fast breathing and heartbeat
• loss of consciousness (passing out)
• seizures
• little or no sweating
• flushed, hot, dry skin
• body temperature rises to 105°F (40.5°C) or higher

What Should I Do if a Child Has Heat Illness?

If your child has symptoms of heatstroke, get emergency medical care right away.

For cases of heat exhaustion or while awaiting help for a child with possible heatstroke:

• Bring the child indoors or into the shade right away.
• Undress the child.
• Have the child lie down; raise their feet slightly.
• If the child is alert, place in a lukewarm bath, spray with lukewarm water, or put cool cloths on their skin.
• If the child is alert and coherent, give frequent sips of cool, clear fluids.
• If the child is vomiting, turn onto their side to prevent choking.

What Can Help Prevent Heat Illness?

• Teach kids to always drink plenty of liquids before and during any activity in hot, sunny weather — even if they aren’t thirsty.
• Make sure kids wear light-colored, loose clothing in warm weather.
• Remind kids to look for shaded areas and rest often while outside.
• Wear sunscreen and hats to avoid getting a sunburn.
• Don’t let kids do intense activities outdoors during the hottest hours of the day.
• Teach kids to come indoors right away if they feel overheated.
• Do not leave kids alone in a parked car.