What this is about
A winter drive starts in the freezing cold and ends in a warm car. Ten minutes down the road, the heater has the car at room temperature.
When the car warms up, you can open your own coat. Your baby is still wearing whatever went under the straps, and it stays on until you stop. That's why a thin outfit with a blanket over the straps works so well: the blanket folds away without unbuckling your baby.
Why a puffy coat comes off for the car seat
A winter coat or snowsuit doesn't go under the harness. Over a puffy coat, the straps can feel tight. But the padding is mostly air. In a crash it flattens at once, and the straps are suddenly loose around your baby's chest.
A thin fleece is fine under the straps. A thick, fluffy one can hold almost as much air as a padded jacket. So go by how much fabric sits between your baby and the straps, whatever the garment is called. Tighten the straps again whenever the outfit changes, too: straps set over a fleece are loose over a bodysuit.
Try this coat test once, with your baby's own coat and car seat.
Is your baby's coat too puffy for the car seat?
Buckle up over the coat
With the coat on, buckle your baby in and tighten the straps. Stop when you cannot pinch a fold of strap at the collarbone.
Take the coat off
2–4 in(5–10 cm) of air
Leave the straps as they are. Lift your baby out, take the coat off and buckle up again. Pinch the strap at the collarbone: any fold you find is air the coat held.
- No fold: thin enough
- A fold pinches up: too puffy
Do this instead
Buckle your baby in indoor clothes and a thin fleece, and tighten the straps. Then lay the coat over them, or put it on backward with the arms in the sleeves.
- Fingers slide off the strap
Baby in the car seat: how warm to dress?
Find the row for today's temperature outside. It shows the whole outfit for the ride, with the blanket on cold days.
24°C and warmer75°F
16–23°C61–73°F
8–15°C46–59°F
0–7°C32–45°F
Below 8°C (46°F), the clothes stop changing. However cold it gets, the extra warmth goes on top of the straps: a light blanket down to 0°C (32°F), and a warm one below that.
Getting from the house to the car
If you use an infant seat (the small one with a carry handle), keep it in the house between trips. A seat at room temperature takes less warmth from your baby than one that spent the night in a cold car. Buckle your baby in where it's warm, lay the blanket over the straps and carry the whole seat out.
A bigger seat stays in the car, and that makes cold mornings a little more awkward. Your baby goes out in a coat or pram suit, and it comes off in the car before you buckle up. Have the blanket ready on the back seat before you carry your baby out, so it goes on as soon as the buckle clicks.
On a day of errands, the coat would come off and go back on at every stop. This is where a car seat poncho helps most: your baby wears it to the car, and it stays on in the seat, lying over the straps.
How to keep your baby warm in the car seat
1. Buckle up in thin clothes
Fasten the buckle, tighten the straps, and slide any chest clip up to armpit level. Then pinch the strap at the collarbone: if your fingers slide off, the straps are snug.
2. Blanket over the straps
Lay a blanket over your baby from the armpits down, so the face stays clear. It goes on top of the buckled straps, never behind the back or under your baby.
3. Fold it down once the car is warm
Once the car is warm, fold the blanket down onto the legs or take it off. If you're the one driving, do it at your next stop, or ask whoever sits in the back.
Which way the car seat faces, and where it goes
From the first ride home, your baby rides facing the back of the car. A young child's head is large for the body, and the neck and spine are still developing.
Which way should the car seat face?
Good: Facing the back
2 yearsor more, in most convertible seats
Your child faces the rear window, with the seat's tall back toward the front seats. Tug the seat where the belt holds it, and check its recline indicator, so the head cannot flop forward.
- Moves less than 1 in (2.5 cm)
- Angle inside the indicator's zone
Good: In a sudden stop
The car stops hard, and your child is pressed back into the seat. Its shell cradles the head, neck and back together and spreads the force.
Not good: Facing forward too soon
In the same stop, the harness holds the body back, but the head keeps going, and the neck takes the strain. Turn the seat around only when your child outgrows its rear-facing limit.
The back seat is the safest place for every child under 13. The middle of it may be best, but only if the seat installs tightly there.
Never put a rear-facing seat in front of an active airbag. An opening airbag hits the back of the seat, right by your baby's head.
Car seats as your child grows
The seat you bring your baby home in is usually the first of two or three. Children move up to a bigger harness seat and, years later, to a booster that uses the car's own seat belt. Each seat has a height and a weight limit on its label.
From birthInfant seat
Up to 22–35 lb (10–16 kg)
It faces the back only and has a carry handle. Most click into a base that stays in the car, so the seat lifts in and out with your baby still buckled in. Many babies reach its height limit before the weight one. Moving up earlier is fine too, for example when the seat gets too heavy to carry, as long as the next seat also faces the back.
From birthConvertible seat
Faces the back to 40–50 lb (18–23 kg)
It is bigger and stays fitted in the car. It faces the back first, in most seats past the second birthday, and later turns around to face forward with the same harness. An all-in-one seat works the same way and becomes a booster at the end.
4 years or olderBooster seat
Until the seat belt fits, 8–12 years
It has no straps of its own. It lifts your child so the car's seat belt lies across the hips and the middle of the chest, away from the stomach and the neck. Your child moves to it only after outgrowing the harness seat.
Car seat footmuffs and covers: which are safe
A car seat footmuff (some shops call it a bunting bag) lines the seat, with slots for the straps, so its padding sits behind your baby's back. Whether that is safe depends on who made it. Many car seat makers sell a footmuff made for their own seats, and the seat's manual or the footmuff's label names the seats it fits. That one is fine to use. A footmuff from another brand, sold to fit any car seat, has never been crash tested with yours, and its padding may weaken the seat's protection in a crash. Padded seat liners and head cushions follow the same rule.
A winter cover that stretches over the outside of an infant seat, like a shower cap, is fine on any infant seat. Nothing goes behind or under your baby, and the seat stays as it came. Leave the face uncovered.
A footmuff inside the seat
It lines the seat, and the straps come through its slots.
- Good: Made for your seat model
- Not good: Sold to fit any car seat
A cover over the outside
Its elastic edge grips the outside of the shell. Inside, the seat stays as it came.
- Good: Fine on any infant seat
Summer heat and hot buckles
In the sun, the metal parts of the buckle can get hot enough to burn. A parked car heats up fast, whatever your baby wears. A cracked window or a shady spot does little to keep it cool. Never leave your baby alone in the car, even for a quick errand.
Touch the buckle first
Before your baby goes in, touch the metal tongues and the seat where your baby sits. If they feel hot, cool the car down first.
Cover the empty seat
When you park in the sun, lay a light-colored towel over the empty seat. It keeps the buckle and the fabric cooler.
Questions parents ask
Can my baby wear a coat in the car seat?
Not a puffy one. Take it off, buckle up, then lay the coat or a blanket over the snug straps. The same goes for older children, and even for adults under a seat belt.
Can my baby wear a fleece, a sweater or a thin jacket in the car seat?
Yes, if it is thin and fits close, about as thick as a sweatshirt. A fluffy fleece, a puffy vest or a padded jacket comes off. If you're not sure, test it like the coat: tighten the straps over it, take it off without loosening them, and buckle up again. If you can now pinch a fold of strap at the collarbone, it was too thick.
Can my baby wear a snowsuit or pram suit in the car seat?
Not a padded one, for the same reason as a coat. A thin fleece suit with no padding can stay on, if it passes the coat test. Take the pram suit along and put it on when you arrive.
What should my newborn wear for the ride home from the hospital?
The same as on any car ride: thin layers under the straps, and the blanket on top if it's cold. A padded going-home suit goes under the straps like a coat, so save it for the stroller. Try the straps on the empty seat before the birth, so they are already set low enough for a newborn.
When can my baby face forward in the car seat?
When your child outgrows the seat's rear-facing height or weight limit. In most convertible seats, that comes after the second birthday. In the UK, i-Size seats must face the back until your child is over 15 months, by law.
My baby's legs touch the back seat. Is that OK?
Yes. Children are flexible and find a comfortable position, and leg injuries facing the back are very rare. Touching legs are no reason to turn the seat around.
How long can my baby stay in the car seat?
For the drive only. Take your baby out as soon as you arrive, and stop for regular breaks on a long drive. Sleeping upright for a long time can make breathing harder for a young baby.
Are car seat ponchos safe?
Yes, used the right way. A car seat poncho is a blanket with a hole for the head, so your baby can wear it on the walk to the car. Before you buckle up, flip the back of it up over the top of the seat. The front then lies over the straps, so nothing thick ends up behind your baby or under the harness.
Can my baby wear a hat in the car seat?
Yes, for the cold walk to the car. A hat doesn't touch the straps, so the coat problem doesn't apply. But babies cool down through the head and face, so once your baby is in the warm car, the hat comes off, even if your baby has fallen asleep.
Check the rear-facing harness
- Harness slots (where the straps come out of the seat back) sit at or below the shoulders.
- The straps are snug. You cannot pinch slack at the collarbone.
- If your seat has a chest clip, it sits in the middle of the chest at armpit level.
Read the instructions for your exact seat. A certified child passenger safety technician can check the seat and harness with you, often for free.
