I remember taking my daughter home from the warm and cozy neonatal intensive care unit (NICU) room in the hospital, and being constantly worried that she wasn't warm enough in our house. It was October in Texas, so our air condition was on constantly, which only exacerbated my fears when it came to the temperature and whether or not my baby was too hot or too cold. Thankfully, I only had to go so far as the internet to figure out how cold your baby's room can be, according to experts. Turns out, babies aren't quite as fragile as they seem (or as us first-time moms believe them to be).
According to The Baby Sleep Site, your baby's room should be between 65 - 72 degrees while they're sleeping. That means you can run the air conditioning at a fairly high rate before you have to worry about your little one being too chilly. You do, however, want to make sure your baby has an extra layer of clothing on, especially if they're brand new.
According to the experts at the Children's Hospital of Philadelphia, babies over 12 months of age are capable of coping with outside temperatures the same way adults can. In fact, if you feel comfortable in your baby's room and they're 12 months old, or older, chances are your baby is comfortable, too, and they won't need any additional layers of clothing to remain comfortable while they sleep. Babies under 12 months aren't able to regulate their own temperature, though, so they should have an extra layer of clothing in order to keep them sufficiently warm throughout the night.
Of course, a "comfortable" temperature for babies is a fine balance. You want them to be warm enough to remain comfortable, but you don't want them too warm to the point of overheating. In fact, a 2008 study from the University of Calgary found that overheating can increase the risk of Sudden Infant Death Syndrome (SIDS), so maintaining a cool and comfortable temperature, especially while your baby is sleeping, is paramount.
Sweating is natural for anyone in their sleep, and because babies spend more time in a "deep sleep "than adults, they are more likely to get sweaty while they're snoozing. Parenting cautions parents to take notice if their babies are sweating during the daytime, however, and especially if their little ones are wearing too many layers and/or the temperature in their living environments are too warm. Again, this can be a sign of overheating.
When your baby is still young enough that he or she needs to be swaddled, you'll likely only want to have your baby sleep in a one-piece zip rather than wearing numerous layers under the swaddle blanket. Once your baby is old enough to roll over and can't be swaddled anymore, you'll want to replace the swaddle with a sleep sack, or thicker pajamas, until your toddler is able to use a blanket.
Per the American Academy of Pediatrics (AAP) sleep guidelines, babies up to 1 year of age shouldn't sleep with pillows, blankets, comforters, or any extra sheets in their crib and/or sleep space. This means that finding the right temperature, and laying your baby down on their back and without anything other than a tightly fitted sheet in their crib, could help everyone at home (yes, including us parents) sleep a little more soundly at night.