How Hot Is Too Hot For Babies? Experts Weigh In

I love when spring weather creeps in and temperatures warm up, a cool breeze still in the air. I could leave it at that — I don't ever want or need the ultra-hot, sweaty temps that come with high summer. If you have an infant, then they probably feel the same way, and that's because hot temperatures are even harder on them as they are on us. Why? Because babies don’t have the ability to control their environment. In fact, hot weather can be quite dangerous for babies, and they need our help to stay cool, safe and comfortable. But, exactly how hot is too hot for a baby outside? While there’s no exact temperature that’s too hot for babies, there are a few essential things to keep in mind when it comes to protecting your baby from overheating in the summer months so that you both can safely enjoy these lazy days.

How can parents protect babies in hot weather?

Overheating isn’t just uncomfortable for babies, it’s downright dangerous, Dr. Tony Woodward, medical director and chief of emergency medicine at Seattle Children’s Hospital, tells Romper. As a general rule of thumb, he recommends keeping brand new infants — a few days or weeks old — mostly inside, and slightly older babies and children out of harms way by trying to anticipate your environment and preparing for it. “A lot of parenting and safety is about anticipation,” Woodward explains. “The thing with babies is that they don't have the ability to control their environment, so they're totally reliant on us to meet their needs.”

If you know it’s going to be hot and you’ll need to be spending time outside, consider the fact that your baby needs help keeping cool. “Babies absorb heat about five times as fast as adults do, but their ability to sweat is still developing,” Woodward explains. “They produce a lot of heat and they get it from the environment, too.”

To protect babies from overheating if you do need to go out in hot weather, remember to:

• Look for shaded or covered areas, and keep baby out of the direct sun.
• Dress your baby in light, loose-fitting clothing with long sleeves.
• Not place your baby in a closed container. That means ideally not in a stroller, bassinet or even a baby wrap. Air flow is extremely important for keeping babies from overheating.
• Apply sunscreen to any uncovered skin.
• Make sure that babies stay hydrated. If your baby is too little to have water, that means offering extra breast milk or formula on hot days.

How do you know if a baby is overheating?

You know that your baby can’t tell you how comfortable or uncomfortable they feel, but exactly what happens to a baby if they get too hot? It’s important to know the signs of overheating in babies, and watch for them when the temperatures rise.

Signs that your baby is overheating include:

• Irritability
• Flushing
• Their body feels really warm. “99 degrees Fahrenheit to 100 degrees Fahrenheit is a normal temperature for a baby, but if they're at 102 degrees Fahrenheit or 103 degrees Fahrenheit, they're much too hot,” cautions Woodward. And if their temperature goes above 103 degrees Fahrenheit, rush them to a hospital.
• They’re not peeing. Babies should urinate about every three hours, at least. If they're peeing less, or the urine is dark in color or has more of an odor, it could be a sign that baby is dehydrated.
• Rapid breathing or panting. Breathing faster is a way that their bodies will to try to get rid of excess heat.

What temperature is safe for babies to be outside?

While there is no perfect rule about this, Woodward says that if it's over 90 degrees Fahrenheit, parents should “be very careful.” It’s not necessarily realistic — particularly if you have older children to tend to — to never leave the house. However, if it’s over 90 degrees Fahrenheit, it’s important to be aware that extra caution is needed to keep your baby safe from overheating. “It takes anticipation and vigilance,” Woodward says.

Hot weather means parents should also take special precautions when traveling in a vehicle with a little one, says Wendy Kirwan, the director of public relations for Kars4Kids. "When it’s not too hot for babies outdoors, it can quickly reach lethal levels of heat inside a car," Kirwan says, adding that at 104 degrees Fahrenheit, a child's internal organs begin to shut down. "Every 10 to 20 minutes, the internal temperature of the car rises 20 degrees."

You should never, ever leave infants or children in a parked car, even if the windows are cracked open, according to the Centers for Disease Control and Prevention (CDC). “Not even for a few minutes,” adds Woodward, because babies can get overheated very, very quickly. Be sure to also check that everyone is out of the car each time you leave your vehicle. “When I think about accident prevention, so much is preventable, but it's hard. If it's your first baby, maybe this seems simple,” says Woodward. “But, if you have other obligations or you have three other kids running around it can be hard. It's really about just anticipation and having a plan.”

What to do if you think your baby is overheating

"Removing the baby from the heat is the best way to protect them," Dr. Marnie Baker, a pediatrician at Saddleback Memorial Medical Center in Laguna Hills, California, tells Romper. "Parents can also take a washcloth, soaked in cool water, and apply it on their baby’s skin, and then fan them with the washcloth. This is a highly effective method to cool them down, without using a dangerous cold water submersion or topical alcohol wipes, which can rapidly cause shifts in body temperature that are not safe."

Other ways to cool an overheated baby, according to Woodward, include:

• Cool them with a wet wash cloth.
• Get them indoors and into a room with air conditioning or in a room with a fan. “You don’t want the fan blowing directly on the baby, but you do want a room with good air circulation,” Woodward explains.
• Hydration, either from breast milk or formula.
• Remove any extra clothing or blankets.

And, as always, when in doubt, contact your pediatrician to address any concerns. Or, if you notice any signs of a high temperature or altered mental state, don’t wait — rush the baby to the emergency room.

How to dress a baby to sleep when it's hot

Babies do not need to be dressed in more layers than adults, and this is true of dressing babies for sleep as well. So, an easy rule of thumb is simply to think about what is comfortable for you, and remembering that it’s a bit harder for babies to keep cool in the heat. If it’s hot, put them to bed “wearing as little as possible,” says Woodward. “Just a diaper or very light clothing is probably best.” And as for the safest room temperature for babies? “You want the room to be in the 70-ish range, ideally mid-70s,” suggests Woodward. “The least you could put on them, the better they will feel.”

To some degree, you can trust your instincts and your own comfort levels when it comes to protecting your baby from overheating and keeping them safe in hot weather. And remember, a little prevention goes a long way. Keep them in the shade or in a cool room indoors, keep them hydrated, dress them lightly, and keep an eye out for signs of overheating. With these prevention tips in mind, you should both weather the heat just fine.

Sources interviewed:

Dr. Tony Woodward, medical director and chief of emergency medicine at Seattle Children’s Hospital

Dr. Marnie Baker, a pediatrician at Saddleback Memorial Medical Center in Laguna Hills, California

Wendy Kirwan, the director of public relations for Kars4Kids