What should my baby wear in a car seat? Coats, layers and blankets
4 min read
Quick answer
In a car seat, your baby should wear thin, close-fitting layers under the harness. The AAP says bulky coats and snowsuits should not be worn under the straps. Buckle your baby in snugly, then lay a coat or blanket over the fastened harness, and remove it once the car warms up.
- Thin layers under the harness
- No puffy coats or snowsuits under the straps
- Coat or blanket over the buckled harness
- Do the pinch test every time
- Take your baby out of the seat when you arrive
Why puffy coats and snowsuits are not safe under the harness
According to the AAP, winter coats, snowsuits and other bulky clothes should never go under a car seat harness. In a crash, the fluffy padding flattens straight away, which leaves extra space under the straps. A harness that felt tight over a coat can suddenly be loose.
Nothing bulky should go under your baby's body or between their body and the harness straps. This includes thick footmuffs or liners that did not come with your seat, as the AAP warns these have not been crash tested with it.
What should my baby wear in a car seat in winter?
The AAP suggests starting with close-fitting layers and adding warmth that does not sit under the straps.
- Base: long-sleeve bodysuit, and tights or leggings
- Middle: trousers and a warmer top, such as a jumper, then a thin fleece jacket if needed
- Extras: hat, mittens, and socks or booties, which keep your baby warm without getting in the way of the straps
- Over the top: a blanket over the buckled harness, or a coat put on backwards over the straps
How to do the pinch test
The pinch test checks whether the harness is snug enough. Do it in the clothes your baby will actually travel in.
- Buckle your baby in and tighten the harness
- Try to pinch a fold in the harness strap
- If you can pinch the strap, tighten it until it fits snugly against your baby's chest
- If it will not fit snugly, take off the bulky layer and put it over the buckled harness instead
Keeping your baby warm without overheating
The AAP suggests keeping the carrier part of an infant car seat indoors when you are not using it, so it starts at room temperature. Make the top layer easy to remove, so your baby does not get too hot once the car warms up. Once you are in a warm car, the NHS advises removing hats and extra layers straight away, even if your baby wakes.
If you use a car seat cover, the AAP says use it only if it has no layer under your baby, and keep your baby's face uncovered. The NHS also warns never to leave a baby in a parked car, which can heat up very fast.
Can my baby sleep in the car seat?
The NHS says a baby nodding off in the car seat during a journey is fine, but lift them out once you arrive and do not leave them in the seat for long periods. The AAP advises moving a sleeping baby to a firm, flat surface on their back as soon as possible. Always follow your seat's own instructions.
Sources
We check this guide against these sources. It is general information, not medical advice: speak to your health visitor, GP or paediatrician about your own baby.
Questions parents ask
Can I put a blanket over my baby in the car seat?
Yes, over the harness. The AAP says you can lay a blanket over the top of the buckled straps. Strap your baby in snugly in thin layers first, then add the blanket. Keep it away from their face, and take it off once the car is warm so your baby does not overheat.
Are fleece jackets safe in a car seat?
A thin fleece is usually fine. The AAP lists a thin fleece jacket as a sensible top layer. To be sure, do the pinch test while your baby wears it. If you cannot get the harness snug against their chest, take the fleece off and put it over the buckled harness instead.
Should my baby wear a hat in the car?
A hat is useful getting to and from the car in the cold, and the AAP says hats, mittens and booties do not interfere with the straps. Once the car is warm, the NHS says take off hats and extra clothing, even if it wakes your baby, to stop them overheating.
Are footmuffs and car seat covers safe?
Covers that go over the top of the seat, like a blanket, are fine if your baby's face stays uncovered. The AAP says use a cover only if it has no layer under your baby, and that anything that did not come with your car seat has not been crash tested with it.