What should a baby wear to bed when the house gets colder?

Quick answer: In a room at 16 to 20°C, most babies sleep well in a sleepsuit inside a 2.5 tog sleeping bag, with no hat and no extra blankets. To check their warmth, feel their chest or the back of their neck. Take a layer off if they're hot or sweaty.

What parents need to know

When the heating comes on, the nursery can be chilly at bedtime and warm by 3am. A room thermometer tells you more than guessing does, and the NHS advises using one to keep the room at about 16 to 20°C.

In colder weather it's natural to want to add more layers. The NHS says babies are better slightly cooler than too hot, because overheating raises the risk of sudden infant death syndrome (SIDS). Small babies aren't good at controlling their own temperature, so you'll need to make the changes for them.

What to put your baby in at each room temperature

Start with the reading on the room thermometer and choose the sleeping bag tog that matches it. NHS sleeping bag guidance links each tog rating to a room temperature range. Then adjust the clothing underneath, and don't add any other bedding.

On a cold night, the NHS says a sleepsuit and a sleeping bag should be enough. If your baby feels cold in their sleeping bag, add a layer of clothing, not a blanket. Keep using the room thermometer and aim to keep the room at about 16 to 20°C.

How to check if your baby is too hot or too cold

Hands and feet are a poor guide. The NHS says cool hands or feet are normal, so check your baby's body instead.

1. Slide two fingers inside the top of their sleepsuit and feel their chest, or feel the back of their neck.
2. If the skin feels hot, damp or sweaty, or their tummy feels hot, take off one or more layers of clothing or bedding.
3. If they feel cool and you're using a sleeping bag, add a layer of clothing underneath, not a blanket on top.

Sleeping bag or blankets

Choosing and fitting a sleeping bag

The NHS says sleeping bags can help reduce the risk of SIDS because babies can't wriggle down under their bedding. The bag should fit well around the shoulders so your baby's head can't slip inside it.

Tog ratings show how warm a bag is. Check the manufacturer's advice on the right tog for winter, and don't put any other bedding in the cot.

Using blankets instead

If you use blankets, put your baby on their back with their feet at the foot of the cot or Moses basket. Use lightweight cellular cotton blankets, tucked in firmly and no higher than their shoulders.

Avoid thick, fleecy or padded blankets. The NHS notes that a folded blanket counts as two blankets, so doubling one over can make your baby too hot.

Hats, radiators and other winter risks

Overheating can increase the risk of SIDS. The NHS advises taking off hats and extra clothing as soon as you come indoors, even if it wakes your baby. These rules apply to every sleep, day or night, for at least the first 12 months (counted from their due date if they were born prematurely):

• No hat for sleep indoors.
• Never use a hot water bottle or electric blanket for a baby.
• Keep the cot or Moses basket away from radiators, heaters and fires, and out of direct sunlight.
• Keep the cot clear of pillows, duvets, cot bumpers, soft toys, pods and nests, which can cover your baby's face or make them too hot.

Frequently asked questions

Should I dress my baby more warmly if they have a cold or a temperature?

No. The NHS says most babies who are unwell or feverish don't need extra clothes, even in winter. Contact 111 or your GP if you're worried.

What about naps in the car on cold days?

Take off hats and extra layers as soon as you get into a warm car. Your baby can fall asleep in their car seat while you travel, but the NHS advises taking them out as soon as you arrive.

Is the advice different for a baby born early?

The same rules apply. If your baby was premature, the NHS advises following safer sleep advice for a year from their due date, not their birth date.