Baby, It's Hot Outside!

The Effects of Summer Heat on Infants

By Teri Brown

When those lazy, hazy days of summer come, we think of lemonade, swimming and enjoying our little ones frolicking in the sun. The last thing we think about is the dangers the heat from that sun may pose for our children.

Hilary Evans, a mother of three from Fort Dodge, La., learned the hard way the effect heat has on infants. One beautiful summer day, she took her 2-month-old baby on a short trip to a nearby grotto to sit in the shade and relax.

"By the time we reached the grotto the sun was in full force, and the heat was unbearable," says Evans. "We tried to walk through anyway, but we were all really hot. Even in the shade our son's cheeks and chest were getting red. We took a break in the snack shop, but as soon as we got back out in the heat, Nathan started crying, and he didn't stop until we got back in the car and turned on the AC. In hindsight, I realize we never should have gotten out of the car."

Evans was lucky, as was Hannah Hayes from Chicago, Ill. She and her 1-1/2-year-old son were attending a family picnic when she noticed her toddler was showing some odd symptoms. "He was running around with all his cousins having a blast, and he seemed fine," says Hayes. "When I brought him in to change his diapers, I saw he was totally flushed. Then he started trembling and when I felt him he was burning up with what felt like a fever. I don't think he had a drop of sweat on him despite the heat."

Hayes' sister asked when the last time the toddler had had anything to drink was, and Hayes realized that her young son had been playing in the extreme heat without any liquids. They gave him some water and bathed him down, and he went right to sleep. When he awoke, he was fine, but it taught Hayes a lesson she never forgot. "I don't know if it was officially heat stroke, but it taught me to pay attention to fluids in addition to sunblock," she says.

Dr. Charles Shubin, medical director of the Mercy Family Care Children's Health Center in Baltimore, Md., believes babies and very young children can be more sensitive to heat than adults. "Heat is lost [or gained] mostly through the skin in humans, so the more skin for your weight you have, the more sensitive to temperature changes you are," says Dr. Shubin.

Overheating leads to increases in body temperature and can lead to heat stroke and/or heat exhaustion (from water loss from sweating), according to Dr. Shubin. Sudden rises in body temperature can lead to "febrile" [feverish] seizures, but it's the rate of rise, not the height of the temperature, that is the cause.

"The obvious signs [of heat stroke and heat exhaustion] would be that the baby feels hot to the touch and wants to drink, as sweating can lead to dehydration if losses aren't replaced," says Dr. Shubin. "Less obvious would be the late signs of changes in responsiveness and behavior, perhaps irritability but usually lethargy."

Dr. Andrea McCoy, associate professor of pediatrics at Temple University School of Medicine in Philadelphia, believes the problem isn't that babies are necessarily more sensitive to heat but that they are unable to cool themselves as easily as adults.

"They cannot move themselves to get out of the heat, take off extra clothes, replenish fluids, etc.," says Dr. McCoy. "They are able to sweat and have a large body surface area through which they lose heat, which is a good thing! However, if a baby sweats and the clothing becomes wet, they have even less ability to evaporate off the heat, especially in a closed environment like a car."

Dr. McCoy's answer to this is to avoid overdressing. "Babies should wear lightweight, loose-fitting clothes," she says. "Avoid being outside during the hottest times of day, typically noon until 3 p.m."

Want to see more?

• Hot, Hot, Hot! Safely Surviving a Heat Wave
• A Bun in the Oven: Beating the Heat during a Summer Pregnancy
• No More Tears? Recognizing the Signs of Dehydration
• Talk about it!