Kids are far more susceptible to heat exhaustion than adults are because their bodies have fewer sweat glands and they aren't able to adapt as quickly to temperature changes. Here's how to keep your kids safe when the heat is on outside:

Normal, hot-weather reactions:

• Heavy sweating, beet-red face, but still a happy appearance
• Rapid heartbeat, breathing hard
• Being very thirsty
• Feeling hot to the touch
• Stitches or muscle cramps

These signs aren't usually worrisome on their own. But keep an eye out, especially if your child's exerting herself on a super-humid day (when sweat doesn't cool the body down the way it does in drier weather) or during a heat wave.

Signs of over-exertion, and possibly heat exhaustion:

• Dizziness, weakness
• Beet-red skin
• Clamminess
• Extreme fatigue that forces him to sit down
• Fainting
• Nausea or vomiting
• A bad headache
• Lack of sweat
• Looking very miserable

Treatment: If your child suddenly complains that he feels weak, nauseated, or dizzy, or if your baby's skin looks pale and feels cool and moist, quickly get him into the shade. Loosen his clothing and give him plenty of water or a drink with electrolytes, such as Gatorade. (Infants and toddlers may be given a commercial rehydrating solution, such as Pedialyte or Rehydralyte.) If his symptoms don't improve in the next hour, or she becomes confused, has trouble breathing or develops a rapid pulse, seek medical help. Call off outdoor play for the day; then, when he's ready to venture out again, encourage water and shade breaks every 15 minutes or so, to prevent another episode.

Seek emergency help: If he becomes confused, loses consciousness, has difficulty breathing, or develops a rapid pulse or shallow breathing, go to the ER. Heat exhaustion may have progressed to heatstroke, which can damage body tissues and, if not treated right away, be fatal.