Should Babies Sleep in Fleece? What Parents Must Know

By Kimberly


You always want what’s best for your child, and with new information coming out as fast as you can read it, it can all get overwhelming. In this post you’ll find up-to-date information for parents of babies in 2021, to answer any questions you may have about that fleece onesie sitting in your child’s closet. So, should babies sleep in fleece?

In general, fleece can be fine for babies to wear while sleeping in cold or chilly weather. In warmer weather and climates, fleece isn’t as safe for sleeping babies as cotton. Wearing fleece in too-warm weather can cause babies to suffer dire consequences should they sleep in this thick material.

The long answer, however, is that one size doesn’t fit all when it comes to what your baby should be sleeping in at night. Depending on your situation and location, your baby could be able to safely sleep in fleece. As always, when it comes to babies, unfortunately, there’s never a standardized answer.

An image of a cute baby wearing a fluffy fleece onesie sucking on a pacifier while sleeping lying on bed blankets.

Should Babies Sleep in Fleece?

Fleece is one type of fabric that can be good for babies to wear – particularly when babies need to stay warm. It can be great in chilly or cold-weather or when a baby’s room tends to get cold (no matter what the thermostat says it’s supposed to be).

Fleece isn’t a super breathable material, though, so it is not the go-to choice for warmer weather or warmer bedrooms. In a too-warm room, fleece will make your baby too hot, which can lead to sweating or overheating.

So should your baby sleep in it? Well, it’s going to depend on what your local weather is, what temperature your house is, and how warm your baby likes to be. It’ll also depend on if your baby will tolerate the fleece fabric. Some babies don’t like it, so then it’s not a realistic option for them.

Is Baby Warm Enough in Fleece Pajamas?

In general, your baby will be warm enough in fleece pajamas if you would be warm enough in them yourself. If fleece pajamas are too hot for you, then your baby shouldn’t wear them, either. If the fleece sleepsuit is too warm for the situation, try a cotton sleepsuit instead.

Babies should sleep in a room between 68 to 72 degrees Fahrenheit, or 20 to 22 degrees Celsius (source). That being said, it’s not always possible to sleep in these conditions. Depending on the time of year, the insulation in your house, and your ability to cool or heat each room evenly, you may have to adjust what you put on your baby to sleep.

If your house gets too cool at night, you might want to consider putting your child in warmer materials. This will keep them comfortable during the night, and let you fall asleep and (hopefully) stay asleep, without worrying about your child’s safety.

The general rule of thumb you may have heard of is that babies should sleep in one more layer than what would be comfortable for you, so if this means throwing on heavier materials, or layering light ones, there are options when it comes to dressing your child for bed.

If you would be too warm in fleece pajamas yourself, your baby will be warm enough in fleece pajamas. Fleece pajamas are designed to keep any wearer – adult or child – perfectly warm while wearing, and are great options if you can’t keep the baby’s sleeping environment between the recommended temperatures.

There should be no question; unless you’re sleeping in frigid temperatures, and are regularly sleeping comfortably in fleece yourself, fleece pajamas will be enough to keep both you and your baby warm.

Living in Utah, we found that fleece pajamas were just right during the winters – but we’re also the kind of people who don’t turn the heat on above 70 degrees Fahrenheit.

When in doubt, don’t forget to layer fleece pajamas with a cotton bodysuit (onesie). That will help. But if you’re finding that your baby is sweaty? Then the fleece is too much. Swap it out for a cotton sleepsuit.

Are Fleece Pajamas Too Hot for Babies?

Fleece pajamas are too hot for babies while fleece clothing is too hot for adults. There are many possibilities where fleece pajamas are too warm for your baby, such as if it’s summer if the room where they’re sleeping is well-insulated if other factors of the house contribute to a warmer sleeping environment. If so, then your baby is likely to be too hot. If you would be overheating in fleece, chances are your baby will be as well.

If you don’t know if the conditions are too warm for fleece, it’s safer to put your baby in something lighter, or of a different material. It’s always safer for your baby to be a little cold at night than too hot.

Pro tip: if you aren’t sure, layer a cotton onesie (bodysuit) with a cotton sleeper with footies. That way, your baby should be warm or cool enough, even if you guessed a little wrong in either direction.

Overheating in babies is currently considered to be one of the factors of SIDS, and so it should be noted that overdressing your baby in the winter months, or anytime, could pose a risk to your child (source).

Studies are constantly underway to look further into this information, but babies fall into deeper sleeps the warmer they are. Overheating could cause them to fall into too deep of a sleep, making it harder (or impossible) to wake them. This isn’t to scare you as a parent, but rather to present the facts as we have them now on overheating’s contribution to SIDS.

So, where does fleece fit into this? Well, what you should know about fleece is that it is a fabric that is designed to insulate, it is made primarily of polyester, and overall it isn’t very breathable. This keeps both you and your baby warm during those cooler winter nights or late summer camping trips. It’s made to ensure the wearer stays warm, either from the fabric itself or from trapping the wearer’s body heat.

This can mean that your baby will be too warm, or is just right, with minor cases being that fleece wouldn’t be enough for them. Monitor your baby if they’re wearing fleece at night. Check and see if they’re sweating (which would indicate they are definitely too warm), or if they’re fussy or seem uncomfortable a couple of hours after putting them down.

Can Babies Sleep in Fleece Sleepsuits?

Like fleece pajamas, fleece sleepsuits can be acceptable in certain conditions. If the baby will be sleeping in a cooler temperature, whether in their bedroom or out on a cooler walk in autumn or winter with their parent(s)/guardian(s), fleece sleepsuits will be enough to keep the baby nice and warm.

It should be noted that fleece won’t inherently cause harm to your baby, and there are certain situations where they could benefit from the extra heat that fleece would provide. It will all depend on your individual situation. Particularly the local weather and climate.

If you aren’t sure, then go talk to your pediatrician about your situation. They will be more aware of temperatures in your area and will be able to give you regional advice.

If you live in Northern Utah like me? Then fleece pajamas are almost a must during the winter – and during most camping trips year-round. But I keep an eye on things – and we bring both fleece and cotton options just in case things change.

An image of Small feet of a newborn Caucasian baby sticking out of a white fleece blanket.

Should Babies Sleep in Fleece?

Babies should generally sleep in clothing that is appropriate for the situation, climate, and location. In other words, it depends.

Fleece won’t overheat your baby in all situations. There are some cooler temperatures that could benefit from a nice fleece pajama set, and keep your baby at the right temperature to sleep the night. However, if you primarily live in a warmer climate or your baby’s bedroom can be maintained at a good temperature, then you are not likely to ever need to dress your child in fleece.

Also, as it is made of polyester, fleece could cause allergy symptoms in babies (or adults) that have an allergy to polyester. If you suspect an allergy, definitely don’t let your baby wear fleece. Allergies are weird, so talk to your doctor about them.

Even if the night will be particularly cool, it is best to test your baby’s reaction to fleece before allowing them to sleep in it for 10+ hours.

Overall, in winter or cooler temperatures, you should be cautious in instances where you can’t monitor the situation closely or haven’t had your baby sleep in fleece in those conditions before.

This isn’t to say you can never let your child sleep in fleece, but if you want peace of mind, alternatives that you can consider for your baby are the following layering options.

Light layers that are easily removed and put on can ensure your sleeping baby stays comfortable.

100% cotton is breathable, which will allow for your young one’s body temperature to be able to regulate. Wearing cotton with a sleeper designed for winter, or a sleepsuit and sleepsack could provide enough warmth for your little one, without the same risks as fleece. It is a nice, less worrisome alternative.

But, if your child is not allergic to polyester, the night will be quite cool, and you’ve got a cute fleece pajama set, then know that you can put your baby in fleece for the night. It’s not a necessity, but it can be a useful tool in your parenting tool belt.

Final thoughts on Fleece Sleepsuits

Fleece sleepsuits aren’t the be-all, end-all of baby pajamas. They’re a great option in chillier or cooler weather. But when it gets warm again? It’s time to change back to the cotton pajamas.

Our kids loved wearing fleece pajamas – especially the ones with the footies. But we also don’t keep the house super-sweltering in the winters. And when we go camping? It can get downright chilly – even during the summer. So having some fleece pajamas is a great option. Just make sure you take some cotton ones as a backup. Trust me.

And because this post has not once yet mentioned it (and also because you can never hear it enough), don’t worry. You’re doing a great job as a parent. We’re here to support you. We’d love you to have access to our subscriber exclusive freebies – that are only available to parents who subscribe to our (totally free) newsletter.


Learning about parenting or sleep training techniques is important to learn from various reputable sources. These are the sources used in this article and our research to be more informed as parents.

  • Garzon, Maaks Dawn Lee, et al. Burns’ Pediatric Primary Care. Elsevier, 2020.
  • “Research On Other SIDS Risk Factors.” Eunice Kennedy Shriver National Institute of Child Health and Human Development, U.S. Department of Health and Human Services,

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