Here's how to protect your baby from heat stroke

Whenever extreme hot weather is predicted, high temps are potentially dangerous for anyone. But your baby is especially vulnerable.

Heat is the number one cause of weather-related deaths in the U.S., but there are no hard-and-fast rules about when to keep your baby indoors. The age of your baby, the humidity, your baby's health and the planned activity all should be considered before making an in-or-out decision.

Here's what parents need to know about heat-related illness and injury in babies:

  • Babies heat up quickly. Infants and small children have more body surface area than body mass, so they gain heat more quickly than adults. If it's hot outside, your baby will overheat before you will.

  • Babies don't sweat as much as adults. Sweating is how the body stays cool, but in babies and young kids, the sweat glands aren't fully mature. Babies can (and do) sweat, but sweating doesn't cool them down as well as it cools adults.

  • Children adjust to heat more slowly. You can adapt to temperature swings much more quickly than your baby can.

  • Kids generate more heat than adults. Children have faster metabolic rates than adults, so when they're on the move, they heat up quickly. According to the American Academy of Pediatrics, during exercise, kids generate up to 20 percent to 25 percent more heat for their body weight than adults.

These simple guidelines can help keep your baby cool and safe this summer:

Pay attention to heat advisories. The National Weather Service will issue a heat alert when the Heat Index is expected to exceed 105°-110°F for at least 2 consecutive days. (The Heat Index factors in both temperature and humidity.) If your area is under any kind of heat warning, it's best to keep baby in cool, air-conditioned locations for the bulk of the day.

Dress for the weather. Ignore the well-meaning grandmas on the bus; your baby does not need a sweater when it's 80 degrees outside! If it's over 75 degrees, your baby will probably be fine in a onesie or other lightweight outfit. (No shoes or socks required!) Of course, it never hurts to keep a sweater tucked in your diaper bag, just in case.

Never leave your baby in the car. Every summer, it seems, a baby dies after being forgotten in his or her car seat. ALWAYS check the backseat before getting out of your car, and never leave your baby in the car, even if you're just running into the store for a few things. Temperatures can rise to deadly levels within minutes, even if the windows are open.

Push fluids. Babies can quickly become dehydrated in hot weather, and dehydration increases body temp even more. Your baby doesn't necessarily need water; breastfed babies tend to meet their increased fluid needs by nursing more during hot weather, so nurse on demand. Sterilized water can be offered to formula-fed babies and babies who are eating solids.

Consider the heat when planning activities. There's a big difference between lounging in the shade and playing in the sun. Keep active outside play to a minimum on really hot, humid days.

Practice sun safety. It's not just the heat you have to worry about, but the sun's damaging rays. Cover your baby's head with a floppy hat, protect her eyes with wrap-around sunglasses and slather on sunscreen (if your baby is older than 6 months). If your baby is younger than 6 months, it's best to keep her out of direct sun.

Know the signs of heat exhaustion:

  • Cool, pale, clammy skin (red, hot, dry skin can be a sign of heat stroke, which is a medical emergency — call 911!)

  • Listlessness

  • Nausea and vomiting

  • Fast, weak pulse

If you notice any of these symptoms, move your baby to a cooler location, apply cool, wet cloths to the skin and have her sip some fluids. If she doesn't seem to be improving, seek medical attention.

A version of this story originally appeared on iVillage. It was published on TODAY.com in 2013 and has been updated.

This article was originally published on TODAY.com