How To Keep Baby Warm In Crib [+ Everything You Need In Baby’s Room!]

On cold nights it's totally normal to want to keep your sweet baby's hands, feet, and face warm and cozy. Infant sleep is enough of a puzzle, there's no need to add something preventable into the mix! Discover how to keep baby warm in their crib all night while reducing risk factors of SIDS for deep restful sleep all around!

5 Best [+ Safest] Tips To Keep Baby Warm In Crib:

Sleep sack or swaddle

While many new parents have heard of a swaddle, a sleep sack is another great option and our suggestion overall.

Swaddles and sleep sacks are like wearing an extra blanket, without the loose bedding in the crib.

Swaddles tend to be more for newborns, as babies who can roll need their arms free for safety reasons. Sleep sacks come in a wide variety of sizes and styles and act as a wearable blanket through the toddler years that keep baby's arms free.

Sleep sacks are more like a baby sleeping bag and feels more like a true wearable blanket. They last longer and generally support baby's development (freedom of movement) better than a swaddle.

Our suggestion is to get a few of these sleep sacks to start. They're a good choice because they transition from swaddle to sleep sack with the option to swaddle traditionally with arms down, or with arms up, and eventually free the arms entirely. You can add an extra layer of clothing as needed under them.

If you need something warmer, we highly suggest splurging on these sleep sacks once your baby goes “arms free.” The unique organic cotton and merino wool blend helps regulate baby's body temperature. If you've ever worn merino wool, you know it's not a gimmick. It really does warm or cool depending on what your body needs. Making it a great option throughout the year, not just the colder months.

First hand review:

When I first saw the price on these sleep bags, I thought “no way!” but then, I started looking at other sleep bags and realizing that because they're sized, I would need to buy at least 3-4 different sizes in order to get my baby to 2 years, and maybe more when we started to consider the different seasons and different TOG levels most other brands offer. When I did the math, this one made sense!

One size will last at least 2 years! We now have two of them and I recommend them to all of my expecting friends! The material is so soft and has a really nice weight to it, but because the merino is temperature-regulating, I don't need different ones throughout the year. My baby seems so comfortable in this and he actually smiles and starts kicking his legs as soon as I lay him down and start to put his sleep sack on. Highly recommend!

It's important to note in accordance with the current sleep safety guidelines from the American Academy of Pediatrics to avoid sudden infant death syndrome (SIDS) that no weighted blankets should be used on a sleeping baby.

Dress baby properly 

While sleep sacks are a great way to avoid loose blankets in a crib by giving your child a wearable blanket instead, the best way to keep them warm is to to dress them appropriately for sleep.

Depending on how cold it is, this could mean long sleeve thermal footie pajamas, baby socks, mittens to cover baby's hands, or even multiple layers. Additionally, you can look for baby pajamas with a TOG rating (more on that in a minute) of 1.0 or higher like these or this.

Many parents love using the Merlin Sleep Suit. While it isn't technically a swaddle or a sleep sack, it's used for transitioning babies out of a swaddle and can also provide some added warmth. It's essentially a big fluffy suit that keeps baby on their back, while giving them a little more freedom with their arms and legs, without being weighted. With this, you'd still want baby socks, footie pajamas, or something else on their feet.

TOG Ratings: Quick Reference Guide to Dressing Baby For Extra Warmth

TOG Ratings are sometimes listed on clothing. These give parents a reference for how warm the clothing is.

Save this for quick reference in dressing your baby appropriately for baby's room temperature:

Dress the bed properly

While it's important to reduce the risk of SIDS by placing baby on a firm, flat surface without loose blankets, sheets, or soft objects that could cover baby's face, you can still choose thick bedding that will provide some warmth for your baby without having too much bedding posing a risk.

Consider a wool, hemp, or organic cotton crib mattress or thick crib sheets for better temperature regulation.

Lay out the room properly

Each room of your home has a specific airflow pattern you should be mindful of to keep cold air off baby's skin. When placing your babies crib in their own room, keep in mind where air vents and returns are, drafty windows or doors, and fan or heater placements.

Set the room to an ideal temperature

Depending on where you live and time of year, the most comfortable temperature is likely between 65 to 75 degrees.

Additionally you may want to keep humidity in mind. Too humid, or not humid enough, can drastically change the temperature in a room. The ideal humidity level is between 40-50% in a room.

We have this humidity and temperature reader for the room to keep a monitor on things.

Safe space heater tips:

NOTE: We advice using a space heater only as a last resort and with a close eye. These are the cause of almost 80% of residential fires (source). 

If you do need to use a space heater, follow fire safety guidelines:

  • Ensure you space heater has an auto-shut off to prevent it from overheating
  • Plug directly into an outlet; not a power strip
  • Place the space heater away from baby's crib and on a hard surface. Avoid placement on carpets, blankets, or other materials that could overheat/catch fire.

Warm the crib

Before placing baby in the crib, warm it up so it's closer to their own body temperature. You can do this a few ways depending on how cold your home is – but be sure to remove ALL of these suggestions before placing baby in the crib.

How to keep crib mattress warm:
  • Place a warm blanket in the crib while not in use; be sure to remove as babies under 1 years old should never sleep with loose blankets or sheets
  • Add a warm or hot water bottle or flax seed heating pad to baby's crib – either freely or under a blanket – to further warm the crib
  • Use an electric blanket in the crib; again remove before placing baby in crib
  • Use a space heater – temporarily – to warm the crib/room

Safe sleep for babies guidelines:

When it comes to keep baby cozy and safe through the night your best bet is to follow the American Academy of Pediatrics (AAP) current safe sleep best practices:

  • Baby should always sleep alone on a flat firm mattress
  • No loose bedding or loose objects as they pose a suffocation risk
  • No weighted blankets
  • If you choose to swaddle, stop swaddling around three or four months – as soon as baby shows signs of rolling
  • Always place baby to sleep on their back
  • Parents should sleep in the same room as baby for the first six months through the first year of life ideally.

As you can see, one of the key factors of safe sleep the AAP suggests is for parents to cosleep (not bed share) by the AAP, this is especially important during times the thermostat is at the colder end of the scale or during an unexpected temperature change of usually colder months or during winter months so parents can ensure a safe warm environment all around.

FAQs about keeping baby warm at night:

How do I know if baby is too cold at night?

The best way to know if baby is too cold during the night time is to take their temperature. Low-birthweight babies are more susceptible to hypothermia.

Feeling a baby's hands or feet is not a good indicator of their body temperature as cold extremities can have more to do with circulation than it does with internal temperature.

Babies who are too cold may not have enough energy to cry out, but may wake frequently. Instead consider the following:

Signs baby is cold at night in crib:
  • Sneezing
  • Pale skin
  • Frequently waking/restless
  • Trunk of baby's body, the chest/back, feels cold

If your baby is getting too cold, bring them to your chest, skin-to-skin, and covering yourselves with warm blankets is a good way to warm baby with body heat until you can get medical attention and a space heater.

Are babies at risk of being too cold at night?

Newborn babies cannot regulate their own temperature so they are most at risk for getting too cold at night.

Once a healthy newborns can establish a consistent body temperature themselves, the risk diminishes under normal environmental circumstances.

It's good to keep in mind, that as long as you dress baby in an extra layer for sleep than you're dressing yourself, they are likely okay.

How can I keep my baby warm at night without swaddling?

A wearable blanket, also known as a sleep sack, is generally the best option. These come in a variety of materials and thicknesses depending on your climate.

Additionally, these are great for babies through the toddler years as they can limit the likelihood of limbs getting wedged between crib rails or that baby will climb out.

What is the warmest sleep sack for babies and toddlers?

A TOG rating of 3.5 is considered the warmest for baby sleep. We suggest getting this one in particularly cold situations.

Additionally, we love these – while a little pricey they are one size and last for years. They use a unique merino wool blend making them appropriate for all seasons too (and yes, they will really keep baby warm in their crib at night!).

How can I keep my baby's room warm at night?

Consider adjusting air vents in baby's room to limit windflow on baby's skin at night, as well as raising the whole home temperature, dressing baby properly, and using a space heater with an auto-shut off safety trigger if absolutely necessary.

How can I warm my baby's crib without blankets?

You can warm a baby's crib without blankets primarily when baby is not in it, so it's as close to their body temperature as possible before you place baby in.

You can do this with non-electrical options like warm water bottles and flax heating pads or with electrical options like a space heater or electric blanket.

For any electrical option, we strongly suggest making sure it has an auto-shut off feature to prevent it from overheating.

How do you keep babies hands warm at night without a swaddle?

Opt for pajamas with hand covering flaps to keep baby's hands warm during colder nights.

Keep in mind, as mentioned above, baby hands are not a good indicator of coldness. Cold hands or feet can be related to circulation, not just internal temperature.

When in doubt, always use a thermometer to check baby's temperature.

Additionally, once baby stops being swaddled they do have the ability to lay on their hands for added warmth if needed.

Rest assured, as long as you're following the other tips in this post under normal environmental and health conditions you likely do not need to stress about babies unswaddled hands.

What’s the ideal room temperature for a baby's bedroom?

While the American Academy of Pediatrics (AAP) has not listed an “ideal room temperature” for baby sleep, studies have found that a room temperature between 68 and 72 degrees Fahrenheit is ideal for most babies.

Again that can still vary depending on your climate and the season, so I like to suggest between 65 to 75 degrees.

Is it better for a baby to sleep in a cold room?

Most babies thrive in rooms in the mid 60s, up to the low 70s. You want a room that's not too hot or too cold for optimal sleep.

Just like with adults, you don't want baby to wake up from overheating or experience a restless sleep fidgeting trying to warm themselves.

Final thoughts on keeping baby warm all night

A good rule of thumb to remember in keeping baby warm in crib all night, is to dress baby one layer warmer than you're dressing yourself for sleep. As a lightly clothed adult, you have the option to add a blanket, babies don't have that freedom. The “one extra layer” rule may ensure baby is wearing enough to stay warm with their own body heat and layers.