Bundle Up, Baby! A Guide to Safely Layering Up in the Car

Wintertime, for many of us, means bitterly cold temperatures and biting winds.  Packing on the thickest, warmest layers possible seems like the most logical thing to do, but did you know that bundling up under a car seat harness or seat belt can be dangerous?

Coat Warnings from Manufacturers
Excerpts from various car seat manuals warn consumers about the dangers of using coats in car seats.

When bulky layers are worn under a 5-point harness it leaves that passenger vulnerable to injuries in a crash (including being ejected from the safety seat itself!).  The reason for this is that even when the harness is tightened over that thick coat (or bunting, or snowsuit, etc.), the jacket will compress in a sudden stop or crash, leaving enough slack in the harness that the safety seat may be unable to protect the child.  While unpleasant to think about, it’s important to remember how extreme crash forces are.  They’re violent enough that they can crush and tear through vehicle frames.  A fluffy jacket or snowsuit wouldn’t stand a chance.  But that does not mean that your family will have to suffer through frigid temperatures.  There are many ways to stay warm safely while in the car.


4 Safe Ways to Keep Your Infant Warm in their Car Seat
There are many safe ways to keep your little one warm when heading out in cold weather

Safely Layering Up

For young babies who haven’t yet developed full head control (typically, babies under 6 months of age or so), special care should always be taken to ensure that their head is not at risk for being pushed forward, and that their airway is not blocked or obscured in any way.

A snug-fitting, warm outfit, paired with a thin, warm hat is a safe way to bundle your baby up in their car seat. A warm blanket tucked over their fastened harness adds a safe layer of warmth.

Dress your baby in a few thin, warm, snug-fitting layers and buckle them into their seat.  Thin, fleece footie pajamas and the like can also be a good option, but snowsuits and buntings should not be used in a car seat.  A lightweight, snug-fitting hat, warm mittens, and/or slippers can also be added. After baby is buckled up, several blankets can be tucked in place over the harness to keep them nice and cozy; I often recommend 1-2 lightweight blankets (flannel or cotton ones work nicely). If you’re able to, pre-warm your car to get the heat going.

If you’re using a rear facing only seat (commonly referred to as an infant carrier) and are buckling baby up before going outside, a few thicker blankets can be placed on top of thinner ones for extra warmth while carrying baby to and from the car.

A “shower cap” style car seat cover goes around the sides of the car seat rather than between the child and the car seat.

shower cap-style car seat cover is a low-risk option which can be especially useful on days where it’s precipitating or very windy outside.  Conversely, the buntings and car seat covers which are designed to go inside of the car seat, behind the child should not be used.  If you already have one, it can be altered so that most of their associated risks are mitigated (see below).
Remember!  While it’s important to keep infants warm, they can overheat so once you’re in the car, layer accordingly.
*Please note: it is critically important to ensure that any blankets/covers, etc do not interfere with a rear facing only (infant carrier) from fully locking into its base!*

Using buntings inside your car seat can introduce dangerous slack & alter the way your seat was designed to work.  Cutting out the entire portion that goes between your child and their seat mitigates those risks.

Toddlers & Older

Some of the aforementioned options continue to be valid possibilities with toddlers, but there are additional ones which are worth mentioning (because who doesn’t like to have choices?!)

The Car Seat Poncho, shown here on a rear facing toddler, can unzip from either the top or bottom which allows optimal access to the harness


Chances are, I will always be partial to The Car Seat Poncho brand because these are the original “car seat ponchos” sold by the woman who designed and invented them!  Their brilliant (reversible!) design features a zipper which can be unzipped from the top of the poncho by the child’s neck, as well as down by their legs.  This makes buckling and unbuckling a breeze, and it means that you’ll never need to flip the poncho over their face/head to gain access to their harness.  The back of the poncho simply gets draped over the top/back of the car seat while the front can stay over the child’s body.   They’re even made right here in the U.S.A.
The Car Seat Poncho has generously offered Super Car Seat Geek readers a coupon for $3 off each poncho with coupon code: SUPERGEEK (offer expires 2/14/18)

The bottom layer of a bag-style “Bundle” product can be placed over a child like a wearable lap blanket

There are, of course, many other brands and styles of ponchos available if you prefer.  Similarly, if you already have one of those bag-style “Bundle” products, the bottom layer can be detached from the top layer and placed over the child like a wearable lap blanket!  Pro tip: if you do this, I’d strongly recommend cutting off the large elastic band, as well as the Velcro around the “arm” openings.

Fleece Jacket

A thin, single-layer fleece jacket can be an inexpensive and effective way to keep kids safe and warm in the car.

Dressing your child in a thin, single-layer, waist-length, form-fitting fleece jacket is one of my favorite tricks.  They are often very inexpensive and surprisingly warm, especially when paired with a cozy hat and mittens!  If your child would like to be extra toasty, simply tuck a warm, fuzzy blanket or two over them after they’re buckled up.  The blanket(s) can easily be removed if your child starts to get too warm.

Packable Jacket

Another alternative to a thicker jacket is a down-filled, packable jacket.  It should follow the same fit guidelines as described above.  With any jacket worn in a car seat, I recommend doing the following “test” to check if it’s a safe choice to wear in the seat:

Thin, “packable” style jackets can be another great way to safely stay warm in a car seat.

1) Buckle the child in the car seat without their jacket on & tighten the harness so that it passes the “pinch test”.
2) Remove the child from the seat without loosening the harness.
3) Put their jacket on, and place them back into the car seat.
4) Buckle them back up.

If you’re able to buckle them up again without having to loosen the harness, or only having to loosen it a very small amount, then the jacket is ok to wear in the seat.  If the harness had to be loosened more significantly, then it is not a safe option.

A “wearable blanket” is a great way to keep older kids cozy in the car

Wearable Blanket

A “wearable blanket” can be used by your child after they’re secured in their seat.  Like a regular blanket or a poncho, it would go over the harness and drape over the sides of the car seat.  This is an especially nice option for older children because it’s usually long enough to cover the child from their neck down to their feet.  Additionally, the sleeves permit the child use of his/her arms and hands while still having them covered.  If the child gets too warm it’s easily removed.

Preschoolers and Older

The ideas listed above are still perfectly fine to utilize as time goes on.  However, once kids start going to school, a very warm jacket is often needed for outdoor-time.  Sometimes it just makes more sense to have a traditional, thick winter jacket.  While those will continue to be unsafe to wear under a safety restraint, the child can wear it out to the car and remove it prior to buckling up.  The jacket can then be put on backwards, over their harness.

This thick jacket can be safely worn in the car when it’s backwards, over the harness

Another trick is to unzip a jacket and pull it to the sides of the harness.  The jacket can be zipped up over the fastened harness if the child desires, or left unzipped.  Note: this is best done with thinner jackets to avoid bulky or compressible fluff behind the child.

This (thin) jacket has been unzipped and pulled to the sides of the harness

Boosters and Beyond

While the “no coats in the car” rule is starting to become more mainstream, few caregivers realize that coats continue to pose safety risks after children transition to a booster seat from their 5-point harness.

Yes, a seat belt can go back and forth to tighten and loosen as needed, and it will lock and tighten in the event of a sudden stop or crash.  However, in order for a seat belt to provide optimal protection, it must be contacting the person’s body, not a fluffy jacket.  When the latter is the case, the passenger is at increased risk for injuries since the seat belt must fully compress the jacket prior to making contact with the occupant’s body.

Thicker jackets should be avoided in the car, even in boosters. If one is worn, unzip it and pull it away from the seat belt.

Jackets should continue to be thin and lightweight, and should not interfere with the seat belt.  The seat belt should make direct contact with the occupant’s lap, and the shoulder belt should lie flat on the occupant’s torso and shoulder.  If a thicker jacket is worn in the car, unzipping it and pulling it to the sides of the seat belt will mitigate many of the risks.

Car seats and seat belts need to be tight in order to protect their passenger.  Bulky clothing can make them too loose even if they feel tight.  Whether you choose to purchase a specialized product, or utilize what you already have on hand, there are a plethora of safe options available to keep the whole family safe and snug all winter long!