November 8, 2021

How to Dress Your Baby for Sleep in Cold Weather

Babies, Newborns, Toddlers

Cold weather is approaching quickly in Northern Virginia, and if you’re farther north, it has probably fully arrived! So with the cold weather, questions about how to keep your baby warm is an important question to ask – how to keep your little one warm when outside playing, in the car as it’s still heating, and when they’re asleep.

And because sleep is my wheelhouse, we’re going to dive in to how to dress your babies and toddlers for sleep in the colder months/winter so every one can continue to sleep peacefully.

What is the Ideal Temperature for a Nursery or Toddler’s Bedroom?

The ideal temperature for a baby’s nursery or toddler’s bedroom is between 68-72 degrees Fahrenheit.

For some people, it’s pretty easy to keep their child’s room at a consistent temperature, so the seasons don’t seem to affect the nursery or child’s bedroom. For others, however, the nursery temperature often changes based on time of day or season, so keeping their child warm (or cool!) is more of a concern.

So here’s everything I want you to know about how to dress your baby or toddler for sleep in cold weather so you have confidence that they are warm…

How to Determine if Your Baby or Toddler is Too Hot or Too Cold

As a new parent, I was so worried about making sure my newborn was warm when she slept. My mom couldn’t believe we’d consider laying her down without a hat on her head, because clearly she’d be too cold otherwise, so for the first 4-5 months of Olivia’s life, she slept with a little baby hat on.

Which, spoiler alert, is NOT safe! There should be NOTHING lose in bed with your baby, and a hat can so easily fall off your little one’s head as they squirm. So no hats! But I was worried about her being cold, which is legit. So…

Your baby’s belly is the best indicator if your little one is warm or too cold. So if their belly, or even chest or neck are cold to touch, then they are likely too cold. (Note that it is totally normal for their hands to be cold at night! I distinctly remember my girls’ cold hands on me as I nursed them at night and it made me nervous that they were cold, until I learned that was normal.)

Oppositely, if your baby’s cheeks are getting more red than normal or if they’re sweating while they sleep, they are likely too warm. And just FYI, it is better to err on the side of your baby being too cool rather than too warm!

Before we keep going, I want to remind you that your baby should not have anything in the crib with them until they’re 12 months old, and at that time you can introduce a lovey, stuffed animal, or small blanket. It’s not until at least two years old that you can safely introduce blankets, and even then toddlers often don’t actually stay under the blankets all night.

So let’s dig into more solutions to keep our little ones warm at night…

My FAVORITE Solution for Keeping Babies and Toddlers Warm at Night during the Winter/Cold Weather

And to keeping them cool during the summer and warm weather…

Woolino sleep sacks!!

sleep sack

I love the Woolino 4-Season Ultimate Sleep Bags, for both babies and toddlers, for SO MANY REASONS, but here are the top three:

1. First, the material the sleep sacks are made of is called merino wool, and it is MAGICAL! I’m no scientist, but the merino wool essentially helps keep your child’s body temperature regulated, whether they’re a bit on the warm side or a bit on the cold side, it uses their body temperature to keep them “just right.”

The Woolino website says, “Merino wool creates a micro-climate around your baby, which maintains a consistent temperature for them. It has the ability to absorb water away from your baby’s skin and release it into the atmosphere during the summer. In winter, it will trap and circulate warm air, keeping your baby warm.”

So in our house, we use them year-round! No need to worry about switching to a winter sleep sack or ditching them in the summer, as that can be rough on consistency and routine. My girls wear the same type of long sleeve cotton pajamas and the same Woolino sleep sacks every day of the year, and have done so since they were 2-4 months old (and now they’re 2 and 4 years old, both still wearing their Woolino sleep sacks!).

And we live in a basement apartment in Northern Virginia, so although the outside temperature doesn’t get as cold as other places farther North, we don’t have control over the temperature and our bedrooms do get colder in the winter (and warmer in the summer). But thanks to these sleep sacks, we don’t have to worry about our girls being too hot or cold.

While Woolino sleep sacks don’t have a set TOG (keep reading!), the website also says,”Woolino sleep bags are recommended to be used in room temperatures 63-77F (17-24C).” Remember, the ideal temperature of your little one’s room is between 68-72 degrees Fahrenheit, so you can see Woolino will help your babe in a wider range of temperatures!

The following chart is helpful in figuring out what your little one should wear under their Woolino, depending on the temperature of their room.

sleep sack temperatures

This is a chart/tag that comes with your Woolino sleep sack!

2. Woolino sleep sacks last forever. Not only is the quality of the material amazing (easy hand-me-downs for younger siblings), but they size up with your little ones. The 4-Season Ultimate Baby Sleep Bags are for babies ages 2-24 months…that’s a sleep sack you can use every day and night for TWO YEARS! The 4-Season Ultimate Toddler Sleep Bags are for toddlers ages 2-4 years…again, two years!

Rather than sizing up every few months, like you have to do with many other sleep sacks out there, these sleep sacks will fit your little one for a long time. And then they’re still in great shape if you have more babies!

3. Woolino sleep sacks are super soft. Many people hear wool and think scratchy, but these sleep sacks are far from it!

(Curious as to why I love sleep sacks, in general? Read this post.)

If you’re wondering about other cold weather sleep sacks or products, it’s important you understand something else first…

Thermal Overall Grade (TOG)- What is it?

Most sleep sacks have a TOG measurement on their label. TOG refers to Thermal Overall Grade, and it’s a type of heat measurement – it measures the amount of insultation, or warmth, a fabric provides. The amount of insulation can be based on thickness of material and/or the type of material, so you can’t simply touch a sleep sack and immediately know if it has a high or low TOG.

And TOG is measured on a scale of <1-3.5, so the higher the TOG, the warmer the sleep sack.

The following chart by SlumberSac shows what kind of clothing is recommended to wear under a sleep sack with the appropriate TOG based on the temperature of your child’s room/sleep space.


The above chart is by SlumberSac.

If your child’s room is on the warmer end, you’ll want a lighter grade sleep sack (or no sleep sack at all) and a light onesie. If your child’s sleeping environment is cooler, you’ll want a sleep sack with a higher TOG and warmer layers underneath.

Popular Newborn, Baby, and Toddler Sleep Sacks with a Higher TOG

Newborn Sleep Sacks for Cold Weather

HALO Cotton Sleepsack Swaddle

The HALO Cotton Sleepsack Swaddle is a great option for your newborn, whether they are still swaddled or transitioning out of the swaddle! And it has a TOG of 1.5.

HALO Micro-Fleece Swaddle

The HALO Micro-Fleece Swaddle is another is a great option for your newborn, whether they are still swaddled or transitioning out of the swaddle. And this one is extra warm, with a TOG of 3.0.

Baby Sleep Sacks for Cold Weather

HALO Winter Weight Sleepsack

The HALO Winter Weight Sleepsack has a TOG of 2.5, so it’s a great option for baby nurseries that tend to be much cooler.

Baby Deedee Sleep Nest

baby deedee sleep sack

The Baby Deedee Sleep Nest also has a TOG of 2.5 and fits babies 6-18 months old!

Baby Deedee Quilted Sleep Nest

Baby Deedee has an even warmer sleep sack, the Quilted Sleep Nest, which has a TOG of 3.5. It also has removable sleeves, if necessary. This sounds like a great option for camping with a baby or young toddler!

Morrison Outdoors Baby Sleeping Bag

Morrison Outdoors has a baby sleeping bag that is made for camping with littles ones 6-24 months old! It doesn’t, however, have a specified TOG.

Toddler Sleep Sacks for Cold Weather

HALO Big Kids Micro-Fleece Sleepsack

Not only do they have a micro-fleece newborn swaddle, but HALO has a Big Kids Micro-Fleece Sleepsack with a TOG of 1.0.

Baby Deedee Sleep Nest for Toddlers

Baby Deedee also has a Sleep Nest for Toddlers with a TOG of 2.5.

Morrison Outdoors Kids Sleeping Bag

In addition to one for babies, Morrison Outdoors has a Kids Sleeping Bag that looks great for camping in cold weather! It does not have a marked TOG on it, but it’s made for camping! It’s truly a wearable sleeping bag for toddlers. (We could have certainly used this on our recent camping trip with the girls!)


The number of sleep products out there can be overwhelming, but if you’re looking for a sleep sack to help keep your little one warm in cold weather (or all year long), this blog post gives you all the details you need to know!

I also have friends and family members who have used flannel crib sheets or flannel/fuzzy pajamas as one more way to keep their little one warm.

A final note, on space heaters…please know that it’s not safe to keep a space heater on for long periods of time, unattended, so I do not suggest putting a space heater in your little one’s room while they’re sleeping. Use one of the recommended sleep sacks above to do that job!

With Grace,