Our bodies, which create a tremendous amount of internal heat, are normally cooled through sweating and radiating heat through our skin. Under certain circumstances, such as unusually high temperatures, high humidity, or vigorous exercise in hot weather, this natural cooling system may begin to fail, allowing internal heat to build up to dangerous levels. The result may be heat illness, which can result in heat cramps, heat exhaustion, or heatstroke.

Heat Cramps

Heat cramps are brief, severe cramps in the muscles of the legs, arms, or abdomen that may occur during or after vigorous exercise in extreme heat. The sweating that occurs with vigorous exercise causes the body to lose salts and fluids. And the low level of salts causes the muscles to cramp.

Kids are particularly susceptible to heat cramps when they haven't been drinking enough fluids. Although painful, heat cramps aren't serious.

What to Do:

Most heat cramps don't require special treatment. A cool place, rest, and fluids should ease a child's discomfort. Massaging cramped muscles may also help.

Heat Exhaustion

Heat exhaustion is a more severe heat illness that can occur when someone in a hot climate or environment hasn't been drinking enough fluids. Symptoms may include:

• dehydration
• fatigue
• weakness
• clammy skin
• headache
• nausea and/or vomiting
• hyperventilation (rapid breathing)
• irritability

What to Do:

• Bring your child indoors or into the shade.
• Loosen or remove your child's clothing.
• Encourage your child to eat and drink.
• Give your child a bath in cool (not cold) water.
• Call your doctor for further advice. If your child is too exhausted or ill to eat or drink, intravenous (IV) fluids may be necessary.

If left untreated, heat exhaustion may escalate into heatstroke, which can be fatal.

Heatstroke

The most severe form of heat illness, heatstroke is a life-threatening medical emergency. The body loses its ability to regulate its own temperature. Body temperature can soar to 106° F (41.1° C) or even higher, leading to brain damage or even death if it isn't quickly treated. Prompt medical treatment is required to bring the body temperature under control.

Factors that increase the risk for heatstroke include overdressing and extreme physical exertion in hot weather with inadequate fluid intake.

Heatstroke also can happen when a child is left in, or becomes accidentally trapped in, a car on a hot day. When the outside temperature is 93° F (33.9° C), the temperature inside a car can reach 125° F (51.7° C) in just 20 minutes, quickly raising body temperature to dangerous levels.

What to Do:

Call for emergency medical help if your child has been outside in the sun exercising for a long time and shows one or more of these symptoms of heatstroke:

• flushed, hot, dry skin with no sweating
• temperature of 105° F (40.6° C) or higher
• severe, throbbing headache
• weakness, dizziness, or confusion
• sluggishness or fatigue
• seizure
• decreased responsiveness
• loss of consciousness

While waiting for help:

• Get your child indoors or into the shade.
• Undress your child and sponge or douse him or her with cool water.
• Do not give fluids.

An Ounce of Prevention

To help protect kids from heat illness:

• Teach kids to always drink plenty of fluids before and during an activity in hot, sunny weather — even if they're not thirsty.
• Make sure kids wear light-colored, loose clothing.
• Make sure your kids only participate in heavy activity outdoors before noon and after 6 PM.
• Teach kids to come indoors immediately whenever they feel overheated.

Reviewed by: Steven Dowshen, MD
Date reviewed: October 2010