How Hot Is Too Hot for a Baby?

Record-high temps in summer can be dangerous for newborns. Here's how to keep your little one safe.

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Summer used to mean carefree days laying out by the pool—but as a new mom, you're now more concerned about your baby's safety in the heat. Is it OK for your newborn to go outside when the temperature goes up, or should you stay inside in the air-conditioning?

Once it gets over 80 degrees, the body has a harder time cooling off—especially for babies. The American Academy of Pediatrics has no official statement on babies and high temperatures, but Dr. Jan Montague, director of pediatrics at Good Samaritan Hospital in Suffern, NY, says to avoid the heat as much as possible. "It is not OK to take a newborn or any infant outside when it's very hot—over 80 degrees or so," she says. "Babies cannot sweat, which is your body's way of cooling itself off, so they can often suffer heat stroke much quicker than an older child or adult." Plus, babies can get dehydrated faster, too.

It's probably not possible to stay inside 24/7 all summer long, but use caution when going out with your newborn. "Keep in mind that babies get overheated much more easily than adults do, so keep [your time outside] short," says Dr. Molly Broder, pediatrician at the Children's Hospital at Montefiore Medical Center in the Bronx, NY. The one time you should definitely not go out is during a heat advisory. In that case, "please keep your baby in a cool, air conditioned location," she says.

When outside with your little one, monitor him closely for signs of heat exhaustion. "If he's overheated, he may get very cranky or irritable, or he may get very lethargic and not wake to eat or drink," Montague says. Also look to see if she is flushed or feels hotter than normal. "As the overheating gets more severe, she might be more sleepy, might vomit, and her skin might go from being moist to very dry," Broder says. "She can develop a fever. A baby with these signs needs immediate medical attention."

To avoid overheating, follow these tips for keeping your newborn cool when it's hot out:

  • Scope out the shade. Shady spots are always going to be cooler than in the sun, so relax with your infant under a tree or covering. "Avoid reflective sun as well," Montague says.
  • Dress your child appropriately. "Lightweight and light-colored clothing that is not too tight will help keep your little one cooler," Broder says. Cotton fabric is the most breathable. Also, "wide-brimmed hats that shade the face and neck are a must!"
  • Keep your kiddo hydrated. "Your infant will need to eat frequently to ensure he or she is urinating, and alert and active," Montague says. Make sure your newborn is having as many wet diapers as usual. For babies under six months, breast milk or formula is best; older babies can have water from a sippy cup or bottle, Broder says. Montague says older infants could even have Pedialyte (one to two ounces per hour).
  • Only use sunscreen on babies older than six months. "Sunscreen is not routinely recommended for children less than six months," Broder says, another reason to make sure your young one is not in the sun. But, "you may also put small amounts of SPF 15 sunscreen on your newborn's face, hands and feet if there is no way to avoid sun exposure," she says. Or, dress him in lightweight long sleeves and pants.
  • Don't cover a stroller or car-seat carrier with a blanket. "The best way to shade a stroller is with a clip-on shade," Broder says. "Even a lightweight blanket like muslin can cause the temperature in the stroller to rise to unsafe levels." It's better to keep airflow moving. "Additionally, if your child is covered with a blanket, you won't be able to see him and tell if he is struggling," she says.
  • Use caution when wearing your infant in a carrier. Body heat can mean that moms who are babywearing need to pay special attention to their little ones. "If mom or dad is hot then their body temperature can transfer to the infant," Montague says. Broder advises both parent and child wear only one layer of light clothing and keep hydrated. "You can help keep your baby cool by spraying his hands and feet with water or by wiping him with a wet cloth occasionally," she says. "A carrier that is lightweight made from thin material will keep him cooler than one made of thick, dark material."
  • Avoid the greenhouse effect in the car. It seems obvious, but don't ever leave your child in a car, even for a few minutes. In addition, don't overdress your newborn for the car. "Since we keep babies rather tight in the car seat and rear-facing, it can get quite hot, so keep him dressed in one light layer only, no hats or feet covered—babies transfer some heat out to cool themselves from their feet and head," Montague says. "Also, make sure the sun is not beating on the infant during your drive." You can use a window shade to avoid a sunburn.
  • Dry out heat rash. If your infant develops tiny red bumps called heat rash, airing it out can be the best treatment. You can also wipe with water and then dry well. "Use cornstarch as a preventable drying agent, never talc as the particles in talc are very small and can be inhaled into a baby's lungs," Montague says. Also, avoid creams and lotions. "Using ointments like petroleum jelly can block the sweat glands even more," Broder says.

Because high temperatures can be so dangerous for newborns, it's crucial to make sure they aren't too hot. Use common sense, and remember, "If you're feeling hot, they are too!" Broder says.

Related: Pregnant? How To Stay Safe on Super-Hot Days