Ontario public health measures
COVID-19 Info | Information sur la COVID-19 | COVID-19 Vaccine Vaccine Receipt | COVID-19 Self-Assessment

Middlesex-London Health Unit

Inner Nav

Infant Car Seat - Winter Safety

All parents want to make sure their baby is safe and warm in the car seat. Canadian winters are cold and babies need to be kept warm when out in the frosty air.


Snow Suits and Bulky Clothing

Snow Suits and Bulky Clothing

To keep your child warm, use regular weight clothing (e.g. polar fleece) and place blankets on top of your child. Do not place your child in a car seat when they’re wearing snow suits or bulky clothing. This material is compressible. In a vehicle collision, compressible clothing can cause the car seat straps to not secure your child properly.


Added Padding

Added Padding

Place your baby in the car seat without adding any material behind. Added padding can flatten and cause the harness to become loose.



Snow Suits and Car Seats

Learn how to safely secure your baby in the car and keep your baby warm. Watch this video on Facebook (video by Healthy Families Hamilton).

Watch Video


How do I keep my baby safe and warm in the car seat?

  • Dress your baby in regular weight clothing that is not bulky, such as polar fleece.
  • Avoid using bulky snow suits with compressible material.
  • Place your baby in the car seat without adding any material behind him/her.
  • Tighten the harness snugly so there is one finger that fits between the harness strap and the baby’s collar bone. The harness should be at the level of, or below the baby’s shoulders when using an infant car seat. Place the chest clip at the baby’s armpit level. Check to see there is no slack in the harness over the baby’s thighs.
  • To keep the baby warm, cover him/her with one, or more warm blankets. A blanket can be draped over the seat when carrying the baby to and from the vehicle. Always follow the car seat manufacturer’s instructions when securing your baby in the car seat and installing the car seat in your vehicle.
  • There are covers available that fit over the car seat, not behind the baby, that do not interfere with the harness system. Check with the car seat manufacturer to see if these are okay to use with your car seat. Keep your baby safe and warm without using aftermarket products.

Safety Risks of Aftermarket Products

In recent years, third- party aftermarket products for car seats have become popular with families. These are any products that did not come with the car seat when it was purchased.

Examples of these products are:

  • Padded car seat bags
  • Added padding behind the baby
  • Harness strap covers and head support cushions

Transport Canada

Transport Canada has found that many of these products can be a safety risk when added to a car seat. Transport Canada regulates the car seats and does crash testing on the seats. Any padding that comes with the car seat has been safety tested. There are no regulations or standards for the aftermarket products. Car seat manufacturers generally state in their instructions not to add any third-party aftermarket product to the car seat.

Safety Risks

There are many safety risks caused by these aftermarket products. The car seat manufacturers state in the instructions not to use bulky clothing or to add anything between the shell of the car seat and the baby.

Padded car seat bags

The padded car seat bag and any added padding behind the baby can cause the harness to become loose around the baby. The extra thickness in the material can compress in a crash or sudden stop and the baby will not be safely restrained in the seat. Transport Canada has a standard that allows for a certain amount of compressibility in the foam of a car seat. Check with the car seat manufacturer before using any product that is added to the car seat. If you choose to use the car seat bag, check to see the product has not changed the proper path of the harness system.

Harness Strap Covers

The harness strap covers are pads that cover part of the shoulder harness system of the restraint. These covers can prevent the chest clip from being at the armpit level of the baby. The chest clip needs to be at armpit level so the harness straps stay in place during a crash or sudden stop. If the chest clip is not in the proper position, there is a risk of the baby being ejected from the car seat.

Head Support Cushions

Head support cushions (head huggers) that are added to the seat can cause slack (loosening) in the harness system. The slots in the head hugger may not line up with the slots in the car seat harness system. The extra slack in the harness may increase the chance of baby getting ejected from the car seat. Instead, rolled up receiving blankets can be used to safely support the baby’s head. If the baby’s head is tilting forward when travelling, check to see if the seat is at the proper angle (45 degrees). Check your car seat instructions to learn how to get the car seat at the proper angle.

Date of creation: December 30, 2014
Last modified on: November 26, 2019

Related Content