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How to Keep Baby Warm in a Crib


After nine months of gestating in a warm and snug home, your newborn is now out in the world.  You may now find yourself wondering how you can keep him warm in a crib.

He looks so tiny in that big crib that he has to be cold without a blanket, right?

There are several ways to ensure that your baby stays warm throughout the night, but none of them involve blankets!

how to keep baby warm in a crib

How to Keep a Baby Warm in a Crib

The best way to keep a baby warm while sleeping is to make sure that the room is kept at the proper temperature.  Around 69 degrees is ideal (source).  If baby still appears to be cold, a sleep sack will provide the warmth of a blanket without the safety risks.  And, as always, a cozy onesie or other clothing will help keep baby comfortable.

Maintaining a Proper Room Temperature

The best way to ensure that your baby stays warm in a crib is to adjust the room temperature.  Take a seat and hang out in your baby’s room for a few minutes.  Spend this time deciding if the room is too hot or too cold.  If you think the temperature is uncomfortable, it is very likely that your baby will too.

What if you aren’t the best judge of temperature?   For example, I carry a blanket from room to room because I’m always cold. Meanwhile, my husband and son often walk around half-naked. 

In this case of familial disagreements, stick with the objective number on the thermostat. The ideal temperature for a baby’s room should be between 68 and 72 degrees.  A room hotter than 72 degrees becomes a SIDS risk factor (source). 

You may want to invest in a baby monitor that also provides a room temperature reading.  With such a monitor, you can view the temperature of your baby’s room from anywhere in the house.  TheInfant Optics video baby monitor is a top-rated monitor that provides a crystal clear image of your infant, safe in the crib, along with a live update of the room’s temperature. 

Sleep Sacks and Sleepsuits

When adults get cold at night, we might just toss on another blanket.  It is not recommended, however, for babies to have any sort of blanket inside their crib.  So, how do you keep the baby warm? 

While loose blankets are unsafe for babies, a wearable blanket is a great option.  Heads up: if you search “wearable blanket,” include the word “baby” unless you want to view several hundreds of results for Snuggies (remember those?).

A wearable blanket, or sleep sack, is a safe sleep alternative.  It looks a bit like a like nightgown, but the bottom closes with a zipper.  A baby typically cannot remove a sleep sack which prevents an accidentally covering his the face.

Sleep sacks are an outer layer, and your baby wears pajamas or a onesie underneath.  Consider the temperature of the baby’s room when deciding how many layers are necessary.  If your infant has flushed cheeks and is sweating, remove a layer or two.  If her hands and feet feel cold, add a layer.

If you’d like to try out a sleep sack, the Zen Nested Bean sleep sack is a best-seller in the sleep sack market.  It features a small weighted egg on the chest area that mimics the feeling of a parent’s hand resting there.  This small touch may be enough to help your baby drift off to sleep peacefully. 

If you have a truly rebellious sleeper, parents swear by the Baby Merlin’s Magic Sleepsuit.  This odd little suit is designed to keep babies cozy, while also muffling the Moro or startle reflex that often wakes neonates during sleep (source).  This suit has helped many parents and babies through sleep regression phases.

If this sleep sack doesn’t help your baby sleep well, it will at least keep them snug and warm in the crib.  Plus, they’ll look like a tiny Stay Puff marshmallow man, and that cuteness makes wearing one worth it.

Space Heater

This is a controversial suggestion because space heaters are the cause of almost 80% of residential fires (source).  If your home lacks a reliable heat source, however, you might need to try one.

If you make the choice to use a space heater, do not place it near the crib.  This prevents accidental burns if it falls over, or if your baby tries to touch it (source).  In fact, the farther it kept is away from your baby, the better.  A good quality space heater will keep your baby warm from a distance.

Choose a space heater with safety features that prevent overheating or a tip-over.   One with an automatic shutoff timer is preferable.

Most importantly, never plug a space heater into a power strip.  This is a huge fire hazard.  Instead, always plug it directly into the wall outlet.

Try a space heater made for nurseries, like the Vornadobaby space heater. It has all of the necessary safety features, including tip-over protection and an automatic safety shut-off.  It even has a childproof switch so that little hands can’t press any buttons.

Signs Baby is Cold in a Crib

Infants who feel cold are more likely to wake up and become fussy throughout the night.  Knowing this, look for these indicators:

  • Cold nose
  • Cold hands and feet
  • Pale skin
  • Fussy

While it’s unlikely to occur in a climate-controlled home, you don’t want a baby to become hypothermic (source).  If you feel your baby is too cold, take steps to help warm her. 

Signs Baby is Too Warm in a Crib

After you have succeeded in making your baby feel warm, you might have done too good of a job!  What are some signs that your baby is too warm?

  • Flushed skin
  • Rapid heartbeat
  • Restless
  • Sweating

Since overheating is a risk for SIDS, always attempt to cool down a warm baby.  This may mean removing a layer of clothing, hydrating, a lukewarm bath, or even removing the baby from the warm room.

Safe Sleep for Babies in a Crib

While your infant is sleeping warm and cozy, you do not want to increase the risk of any sleep-related deaths.  Let’s review safe sleep practices. 

SIDS, or Sudden Infant Death Syndrome, is every new parent’s worry and worst nightmare.  Most parents will readily admit to checking their newborn’s breathing throughout most of the night.

The unpredictability of SIDS causes parents to feel as if they have no control over whether or not it occurs.  While no one can fully prevent SIDS, all parents can take precautions to reduce the risk.  Following the CDC’s safe sleep practices can significantly reduce the chance of sleep-related deaths, including SIDS.

First and foremost, the American Academy of Pediatrics recommends room sharing during the first year of life (source).  This means moving a bassinet or crib into your room.  If anything should happen, mom or dad are nearby. 

Bedsharing is not recommended as it is a risk factor for SIDS.  Babies should be in the parents’ room, but on a separate surface intended for infant sleep.

Babies should always be placed on their backs for naps and bedtime.  This is the safest position under 12 months old.  Infants who are developmentally able to roll in both directions should always begin the night on their backs.  If they roll themselves over in the middle of the night, you don’t need to repeatedly return them to their backs (source).

In addition, the AAP warns against your baby becoming overheated while sleeping.  This is because babies cannot fully regulate their own body temperatures (source)

Lastly, it is important to keep items out of your baby’s crib.  This means no stuffed animals, pillows, or blankets.  Babies may have a pacifier though (these are proven to help decrease SIDS occurrences)! 

FAQs for Keeping Baby Warm in the Crib

When can a baby have a blanket in their bed?

The American Academy of Pediatrics strongly discourages the use of any sort of blanket item inside of a baby’s crib.  Loose blankets, pillows, wedges, and stuffed animals all increase the risk of SIDS.  This includes Loveys (stuffed animal blankets) as well.  These items are all infant suffocation hazards.

By definition, SIDS only occurs in infants, ages 1 year or younger (source).  After the first birthday, the risk of SIDS decreases. However, rare sudden unexplained deaths in childhood have occurred, so it is still best to avoid king-sized quilts and throw pillows (SUDC).

If your baby is comfortable with the current crib arrangement, there’s no reason to force the use of a blanket.  As time goes on, your toddler may become interested in one.  Until then, if she’s comfy, let sleeping toddlers lie.

Do babies sleep better in cold rooms?

The idea that babies sleep better in cold rooms is a popular one.  It may stem from the fact that adults typically sleep better in chilly rooms. The notion also could have been adapted from the Nordic parent tradition of putting their babies outside for naps.  Yes, in Nordic countries, it is a common practice for babies to nap outdoors (usually in strollers).  This isn’t a new trend;  it’s been happening for decades.  This practice, however, may not be acceptable to parents of other cultural backgrounds.

While some parents believe that babies sleep longer in cooler ambient temperatures, others claim that babies wake frequently, and are fussy when cold.

Does this mean that a cooler thermostat setting is best?  In the end, the decision is based on your preference.  Just check on your baby frequently to make sure she doesn’t become too cold.

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

This is a contested topic, but the Sleep Foundation recommends a temperature of 69 degrees (source).  Experts tend to err on the side of caution with this temperature suggestion.  Most medical blogs recommend a range of 68 degrees to 72 degrees.  The general consensus, however, is to avoid overheating the baby.

Within this recommended temperature range, it’s up to you to decide which number to choose.  Check on your baby throughout the night to determine which room temperature seems best.  Every infant has a different comfort level.  You’ll need to discover this for yourself!

Should I cover my baby’s hands and head to keep them warm in a crib?

No, you should not cover your baby’s head at night.  Parents may think that a hat or beanie would be a completely reasonable piece of clothing for keeping a baby warm at night. After all, don’t we lose body heat from our head?

While this may be true, it doesn’t mean that your baby should wear a hat while sleeping.  Hats can slip down over a baby’s face in the middle of the night, and become a suffocation risk.  In addition, since heat is released from the head, wearing a hat may increase the likelihood of overheating.  

On the other hand, it is fine to cover his little hands.  Not only do tiny mitts keep your baby’s hands warm, but they also prevent your baby from scratching himself with those sharp baby nails!

Final Thoughts

As parents, we just want our babies to be warm and cozy in their cribs in order to have sweet dreams.  The obvious choice of offering a blanket goes against the AAP’s safe sleep guidelines, and increases the risk of SIDS.  Some parents may feel at a loss to keep their babies warm at night, but, rest assured, you can!

Instead, maintain a comfortable temperature in the baby’s room, and frequently check for signs that he is too cold or hot.  Dress your baby warmly, and possibly use a sleep sack or wearable blanket.   Most importantly, at all times, practice safe sleep! 

Sources

  1. The Best Temperature for Sleep: Advice & Tips, www.sleepfoundation.org
  2. Ambient Temperature and Sudden Infant Death Syndrome in the United States, www.ncbi.nlm.nih.gov
  3. Moro Reflex…, www.ncbi.nlm.nih.gov
  4. https://www.aappublications.org/content/33/12/32.6, www.aappublications.org
  5. Warmth and Temperature Regulation, www.chop.edu
  6. Safe Sleep for Babies, www.cdc.gov
  7. https://pediatrics.aappublications.org/content/138/5/e20162940, pediatrics.aappublications.org
  8. Sudden Infant Death Syndrome: An Overview, www.ncbi.nlm.nih.gov
  9. The babies who nap in sub-zero temperatures, www.bbc.com
  10. What Is the Best Room Temperature for Baby?, www.healthline.com

Medically Reviewed by

Dr. Alexander began her pediatric career at Elizabeth Pediatric Group of New Jersey in 2000, and has practiced at Pediatricare Associates of New Jersey since 2005. After graduating from Kalamazoo College and Michigan State University College of Human Medicine, she completed her pediatric training at Overlook and Morristown Memorial Hospitals. She is board certified in General Pediatrics. In addition to pediatrics, Dr. Alexander pursued her interest the culinary arts with study at the French Culinary
Institute. In 2007, she opened Global Palate, LLC, catering small group events for six years. Dr. Alexander has also been a professional writer and editor since 2018, engaging in a variety of medical editing and writing projects.



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