When the temperature drops, it’s natural to want to wrap your little one up in a thick winter coat, snowsuit or padded jacket before heading out in the car.
But when it comes to winter coats and child car seat safety, there’s an important rule to remember:
Bulky coats should not be worn in a car seat.
The reason is simple: a thick coat can create extra space between your child and the harness. In a collision, the padding in the coat can compress, potentially leaving the harness too loose to restrain your child as intended. BeSafe specifically advises avoiding puffy clothing because it can prevent the harness from being tightened sufficiently.
So, how can you keep your child warm in the car without compromising the fit of their car seat?
Why can't my child wear a winter coat in their car seat?
A five-point harness needs to sit snugly against your child's body.
A thick winter coat or padded snowsuit adds a layer of bulky material between your child and the harness. Although the harness might appear tight when you buckle your child in, that material can compress significantly during a collision.
This can create additional movement before the harness properly restrains your child.
UK road safety guidance recommends removing thick coats before securing children in their car seats.
How should I dress my child for the car in winter?
The easiest solution is to dress your child in thin, warm layers rather than one thick, padded layer.
For example:
- A long-sleeved base layer
- A jumper
- Warm socks
Place your child into their car seat and secure the harness without their bulky coat underneath it.
Once the harness is correctly tightened, you can add warmth over the top.
How can I keep my baby warm in a car seat?
For babies, this can be particularly important as they can get cold quickly.
Instead of putting a thick coat or snowsuit underneath the harness, consider using thin layers and an appropriate blanket over the top of the secured harness.
A blanket should not interfere with the harness or cover your baby's face. We recommend removing coats before securing a child and using a blanket around the child instead, keeping it below armpit level.
If you're considering a footmuff or other car seat accessory, always check that it is specifically approved or recommended for use with your car seat. Never add an accessory between your child and the harness unless the car seat manufacturer says it is safe to do so.
What about winter coats in a high-back booster seat?
The same principle applies when your child has moved from an internal harness to a car seat using the vehicle's three-point seat belt.
A bulky coat can affect how the adult seat belt sits across your child's body.
The lap belt should sit low across the pelvis/hips, while the diagonal section should sit correctly across the shoulder and chest.
It's best to remove a bulky winter coat before fastening the seat belt and add warmth over the top instead.
The simple winter car seat check
Before setting off, take a few seconds to check:
- Remove bulky coats
Take off padded jackets, thick winter coats and bulky snowsuits before securing your child. - Check the harness
Make sure the harness is correctly positioned and tightened according to your car seat manufacturer's instructions. - Check the fit regularly
Children grow quickly, and the harness may need adjusting as they get taller and their clothing changes. - Add warmth over the harness
Use suitable layers or a blanket over the secured harness rather than placing bulky clothing underneath it. - Check your car seat instructions
Every car seat is different. Always follow the instructions supplied with your specific seat.
What do car seat manufacturers say?
Car seat manufacturers including BeSafe emphasise the importance of avoiding bulky clothing underneath the harness.
BeSafe's guidance specifically states that puffy clothing can prevent the harness from being tightened fully. Their car seat instructions also emphasise positioning the harness correctly over the child's shoulders and securing it appropriately.
Manufacturers such as Axkid and Avionaut also provide detailed guidance around the correct use and installation of their car seats. As with any child restraint, the manufacturer's individual instructions should always take priority when it comes to compatible accessories, fitting and use.
Does this mean my child has to be cold in the car?
Not at all.
The key is where the warmth sits.
Rather than putting a bulky coat between your child and their harness, dress them in thinner layers and add warmth once they are safely secured.
This is particularly useful for short winter journeys, where it can be tempting to simply leave a coat on because you're only travelling a few minutes.
Remember: a short journey still requires the same level of restraint as a long journey.
Can I put a blanket over the car seat harness?
A blanket can be used to help keep your child warm after they have been correctly secured in their car seat, provided it does not interfere with the harness and does not cover their face.
For babies and younger children, make sure the blanket stays safely below their shoulders/armpits.
Always check your car seat manufacturer's instructions before using any additional accessories.
What about a car seat footmuff?
Footmuffs and cosy accessories can be useful in colder weather, but not all footmuffs are suitable for use with every car seat.
The important question isn't simply whether a product is marketed as a "car seat footmuff"- you need to check whether it is compatible with your particular car seat and whether it affects the harness or its positioning.
If you're unsure, check the car seat manufacturer's guidance before use.
Winter car seat safety: the key takeaway
You don't need to choose between keeping your child warm and keeping them safely restrained.
Remove bulky winter coats before fastening your child into their car seat, secure the harness correctly, and then add warmth over the top where appropriate.
It might take an extra minute when you're rushing out on a cold morning, but getting the harness fit right is one of the most important things you can do every time your child travels in the car.
Quick FAQ
Can babies wear coats in car seats?
Babies should not wear bulky winter coats or padded snowsuits underneath a car seat harness. Use thin layers instead and add warmth over the correctly secured harness.
Can my toddler wear a puffer jacket in a car seat?
A bulky puffer jacket should be removed before your toddler is secured in a harnessed car seat, as it can prevent the harness from fitting closely against their body.
Can my child wear a fleece in their car seat?
A thin fleece may be less bulky than a winter coat, but you should always make sure the harness can still be tightened correctly against your child's body and follow the car seat manufacturer's instructions.
Can I put a blanket over the car seat harness?
A blanket can be used over a correctly secured harness, provided it doesn't interfere with the harness or cover your child's face. Keep blankets below armpit level for younger children.
What should my child wear in a car seat in winter?
Thin, warm layers are preferable to bulky coats. Once your child is correctly secured, you can add warmth over the harness where appropriate.
Why are winter coats unsafe in car seats?
Bulky coats can create extra space between the child and the harness. In a collision, the coat's padding can compress, potentially reducing how effectively the harness restrains the child.