Dressing a baby for nighttime sleep can be a surprisingly stressful task: will he be too hot in this or too cold in that? Since professional advice across the board warns against putting a blanket over an infant to sleep, deciding on the right sleepwear is the only factor you can safely control. So with warmer days on the horizon, what should your baby wear to sleep in the summer?
In an interview with Romper, Jeanne Faulkner, a nurse and host of Common Sense Pregnancy and Parenting Podcast, says that a good rule of thumb is to dress your baby in one layer more than you'd wear if you were sleeping in the same room. Faulkner assures parents that on warm nights in rooms without air conditioning, a single onesie is likely enough to keep baby comfortable. If the room is air conditioned, of course, another layer will likely be called for.
If you think you might be piling too much material on Junior, you're not alone. Heather Turgeon, author of The Happy Sleeper: The Science-Backed Guide to Helping Your Baby Get a Good Night's Sleep- Newborn to School Age wrote for Babble that, "One of the most common missteps we see in sleep consultations is people overdressing their babies. There’s a misconception that warmer equals sleepier, but the opposite tends to be true."
Turgeon noted that while adults are accustomed to being fully covered while they sleep (and tend to project that preference onto their babies), infants don't know the difference and don't mind having their toes and legs exposed in appropriate temperatures. She likened it to our preference for using pillows, which babies are perfectly comfortable doing without.
If your baby is a newborn, you might still be choosing to swaddle to help contain their startle reflex, in which case lightweight swaddling blankets are popular and easy to find. But according to The Baby Sleep Site, babies around 3 to 4 months of age are usually phased out of swaddles due to the risk of rolling over and getting caught in the blanket.
Dressing your baby for summer sleep should be determined by your regional climate, temperature of your house, and presence of an air conditioner, so there's no one-size-fits-all answer for every family. But according to the professionals: when in doubt, less is more. As overheating can be dangerous for babies, you should err on the side of fewer layers — you can always add more if your baby seems chilly or uncomfortable.