A guide for parents
Dressing a baby for winter: what they actually need
Thin layers rather than thick ones, one safety rule about car seats, and how to tell whether they're actually too cold.
Your instinct with a tiny baby in December is to pile another layer on. Usually the better answer is a thinner one, and there's one place where that extra layer is genuinely dangerous.
What a baby needs to wear in winter
| Where | What they wear | Watch for |
|---|---|---|
| Indoors | Vest and sleepsuit, plus a thin fleece or cardigan if it is cold | No hat indoors, they overheat |
| Out in the pram | Add a pramsuit, hat and mittens | Hat off the moment you go inside |
| In the car seat | Coat off, blanket over the harness | Never a padded coat under the straps |
| Sleeping | Sleeping bag, following its own guidance | Room 16-20°C, nothing loose in the cot |
For a British winter that's genuinely the list, in whichever size they're currently in. Everything else is duplication or something they will wear twice.
Thin layers, not thick ones
Several thin layers trap warm air between them and can be removed one at a time as you go from a cold street into a hot shop. One thick coat is all or nothing, and a baby can't take it off when they get warm. Guidance from health services is consistently the same: thin, easy-to-remove layers rather than heavy ones.
The car seat rule
This is the one to know, and plenty of parents don't.
Take the coat off before you strap them in. NHS guidance is explicit: remove outdoor clothing such as a winter coat or bulky layers before putting a baby in a car seat, and use a blanket over the top if you're worried about the cold.
A padded coat compresses in a crash. The harness feels tight when you buckle it, then the padding flattens on impact and the straps go loose at the moment they need to hold.
The pinch test is the quick check. Strap them in wearing the coat and tighten the harness. Unbuckle without loosening the straps, take the coat off, and buckle them back in. If you can now pinch slack in the webbing at the shoulder, the coat was too bulky.
A blanket tucked over the harness, or a cover approved for that seat, does the same job safely. Nothing goes between the child and the straps.
How to tell if a baby is too cold
Not by their hands! Babies have freezing hands more or less permanently and it tells you nothing at all.
Feel the chest or the back of the neck. Warm and dry is right. Cool means another layer. Clammy or sweaty means one fewer, and overheating is the more common problem indoors.
And they can't regulate their own temperature or pull a layer off, so the noticing is entirely down to you. They won't tell you.
Sleeping in winter
The room matters more than the clothing. Somewhere between 16 and 20 degrees is the recommendation, and cooler is safer than warmer.
Sleeping bags are sized by TOG, but the TOG is only half the story because what they're wearing underneath counts too. Every bag comes with its own guidance for what to pair with it at a given room temperature, and that guidance is more reliable than a general chart, since bags differ.
No hats indoors, and nothing loose in the cot. If you want the detail, the Lullaby Trust is the source worth reading rather than a blog.
Winter clothes are the worst value in the wardrobe
And here's the bit nobody says out loud.
| Item | Price | Times worn | Per wear |
|---|---|---|---|
| Snowsuit | £30 | ~15 | £2.00 |
| Winter coat | £35 | ~90 | 39p |
| Jumper | £12 | ~100 | 12p |
A snowsuit costs sixteen times as much per wear as a jumper. A coat costs three times, and the same pattern runs through the whole wardrobe. Both are outgrown long before they wear out, which is why they're the things most likely to be sitting in a loft in perfect condition.
The car seat one genuinely shocked me when I found out. I had been doing it wrong for months.
🌱 Which is exactly what a swap is for
A barely-worn snowsuit that no longer fits is worth almost nothing to sell and a lot to a family whose child is now that size. That's the whole idea behind Swapaboo.
You photograph what your children have outgrown, we check and value each piece, and that value becomes credits you spend on the next size from another family. Coats and snowsuits are worth the most, because they cost the most new.
Everything is checked and graded before it lists, and the condition is shown before you claim it. The only money that changes hands is the delivery or collection, from £1.99.
We're opening in small batches and it's invitation only for now.
Common questions
How many layers should a baby wear in winter?
Generally one more thin layer than you are wearing, and thin layers rather than thick ones so they can come off one at a time. A vest, a sleepsuit and a warm middle layer covers most British winter days indoors, with a pramsuit added for going out.
Should a baby wear a coat in a car seat?
No. NHS guidance is to remove a winter coat or bulky layers before strapping a baby into a car seat, and to use a blanket over the top instead if they are cold. Padding compresses in a crash and leaves the harness loose at the moment it needs to hold.
How do I know if my baby is too cold at night?
Feel their chest or the back of their neck rather than their hands, which are almost always cool. Warm and dry is right, clammy means too warm. Overheating is the more common problem, and a room between 16 and 20 degrees is the usual recommendation.
What TOG sleeping bag does a baby need in winter?
It depends on the room temperature and what they are wearing underneath, and bags differ from each other. The guidance printed on the specific bag is more reliable than a general chart, and the Lullaby Trust is the source worth checking for safer sleep advice.
Does a baby need a snowsuit?
Only if they will be outside in a pram in cold weather, and it is one of the least-used items you will buy. Expensive, worn on a handful of occasions, and usually outgrown by spring, which is why so many are sitting in lofts in near-perfect condition.