To sleep well and safely, babies need to be not too hot and not too cold. Here are some tips to help you get your baby’s temperature ‘just right’.

Choosing the right clothes
Dress your baby in enough warm clothes to keep her warm without blankets. Once she can roll over, she can get out from under them and get cold. If you dress your baby in layers of fitted clothing, you can add or take away layers as the temperature changes.
Hats and bonnets
Babies can overheat quickly if they wear hats or bonnets to bed. In fact, heat escapes through their heads and faces, so babies can only cool themselves down if their heads are uncovered. Keep your baby’s head uncovered in bed to make sure he stays around the right temperature. Also note that headwear in bed can be a choking hazard.
Take off your baby’s hat or bonnet when you go indoors or into any closed or warm space, such as a car, so she won’t get too hot.
Baby’s temperature
Your baby’s hands and feet might feel
cool, but this isn’t a good indication of his temperature. Find out how
hot your baby really is by feeling his back or tummy.
If you use a baby carrier or sling, keep in mind that your baby will be warmed by your body heat as well as her clothes and wraps.
Room temperature
If your baby’s room is too warm, you could use a plug-in floor fan to
keep the room at a comfortable temperature. As an added bonus, the
background whirring sound a fan makes might help block out sudden
noises that could wake him.
An infant sleeping bag can be a good option. A correctly sized sleeping bag is the best way to keep your baby’s head and face uncovered, and helps reduce the risk of SIDS. It can also help prevent your baby from rolling onto her tummy during sleep, and contain her legs so they don’t hang out through the cot’s rails. If your baby needs extra warmth, dress her in layers of clothing within the sleeping bag, but keep this appropriate to the temperature of the room.
Check that it’s impossible for your baby to slip down into the bag and become completely covered. SIDS and Kids Australia recommends that you use a sleeping bag that has a fitted neck and armholes but no hood.
Wrapping helps your baby settle for sleep, as well as stay in the safe sleeping position on his back. It’s best to use lightweight cotton or muslin wraps. If you choose to wrap your baby, make sure the wrap doesn’t cover his head, ears or chin – wraps that are too high can obstruct your baby’s breathing and cause him to overheat.
Raising Children Network thanks SIDS and Kids Australia for their helpful comments on earlier drafts of this article.
SIDS and Kids (2005). Frequently asked questions. Retrieved April 11, 2006, from http://www.sidsandkids.org/documents/FAQSept2005.doc
Task Force on Sudden Infant Death Syndrome (2005). The changing concept of Sudden Infant Death Syndrome: Diagnostic coding shifts, controversies regarding the sleep environment, and new variables to consider reducing risk. Pediatrics, 116, 1245-1255.
Wilson, C.A., Taylor, B.J., Laing, R.M., Williams, S.M., & Mitchell, E.A. (1994). Clothing and bedding and its relevance to sudden infant death syndrome: Further results from the New Zealand cot death study. Journal or Pediatrics and Child Health, 30, 506-512.