What Should Baby Wear to Bed? A UK Guide to Room Temperature and Tog

What your baby wears at night should be based on the temperature of the room they are sleeping in, not the temperature outside or the season. A well insulated bedroom and a draughty one can differ a lot in the same week.

A room thermometer near the cot, away from radiators and windows, lets you check rather than guess.

The Lullaby Trust suggests a room temperature of between 16°C and 20°C for your baby's sleep. If the room is outside that range, adjusting the room is usually the better first step.

Sleeping bags differ in fabric, fit and tog, so what to wear underneath depends on the product. The Lullaby Trust and the NHS both make the product guidance important. The NHS also gives general tog ranges; exact clothing combinations depend on the bag.

• Tog and clothing. Check the label or instructions for the tog to use at your room temperature and what to dress your baby in underneath.
• Minimum weight and size. Only use the bag if your baby meets the manufacturer's minimum weight, and choose the right size for their weight and height.
• Fit. The neck and armholes should be fitted so your baby cannot slip down inside the bag. No hood.
• Nothing extra on top. Do not add blankets over a sleeping bag.

Using blankets instead. Properly secured lightweight blankets are an alternative. Put your baby in the feet to foot position, with their feet at the foot of the cot, and tuck the blankets in firmly no higher than their shoulders.

Every baby is different. Use the product guidance as a starting point, then check your baby and adjust. If your baby was born early, had a low birthweight or has health needs, ask your midwife, neonatal team or health visitor for advice that fits them.

The NHS guidance on dressing a baby is short and worth reading in full. The parts that matter at night are these.

• Comfortably warm, not hot. Babies do not need to be wrapped up for sleep the way an adult might want to be. The NHS position is that overheating is the risk to watch for, rather than a baby being slightly cool.
• Check the chest or the back of the neck. Not the hands, not the feet. Cool hands and feet are normal in a baby and are not a sign that they are cold.
• Head uncovered indoors. The NHS advises against hats for sleep indoors, including in cold weather.
• Nothing over the face. The cot stays clear and your baby's face stays uncovered.

The full guidance is on the NHS page on dressing a newborn, which is worth reading in full.

The Lullaby Trust is the UK charity that funds research into sudden infant death syndrome and publishes the safer sleep guidance most UK health visitors work from. Their position on night dressing covers a few specific points.

• Room temperature. Keep the room between 16°C and 20°C.
• Overheating. Getting too hot is a known risk factor for SIDS. Their guidance is to dress a baby for the room temperature and to check regularly rather than dressing for the coldest possible outcome.
• Head uncovered. Babies lose heat through their heads and faces. Hats should be removed for sleep indoors. A hat can also slip down over a baby's face during the night.
• Bedding. Use a baby sleeping bag that fits, or properly secured lightweight blankets tucked in firmly no higher than your baby's shoulders, with your baby's feet at the foot of the cot. No extra blankets over a sleeping bag.
• Sleeping bag guidance. Follow the manufacturer's guidance on tog, clothing and minimum weight, with a fitted neck and armholes and no hood.

Read their full guidance on dressing your baby for sleep.

Tog measures thermal resistance. In plain terms, it is how much warmth a sleeping bag traps. Higher number, warmer bag. It says nothing about quality, fabric or price.

Which tog to use, and what goes underneath, depends on the specific bag and your room temperature, so use the manufacturer's guidance for the bag you own. Clothing underneath adds warmth too, which is why the product's own guidance pairs each tog with what to wear.

Never double up. Two sleeping bags at once is not the same as one warmer bag, and it interferes with the fit that keeps your baby's face clear.

Weighted bags and weighted blankets are not recommended for babies. They are marketed for sleep and they should be avoided.

Many UK bedrooms cool overnight, especially if the heating goes off. A room thermometer near the cot lets you see what the room is actually doing.

If the room changes a lot overnight, adjust the room where you can, and check your baby's chest or the back of their neck when you check on them. The forecast is not a substitute for the reading in the room.

The reverse matters in summer. A room that is comfortable at eight can still be climbing at eleven if the house has been absorbing heat all day.

British houses are built to hold heat in, which is a problem for about four nights a year.

On warm nights, dress your baby in fewer layers and follow your sleeping bag manufacturer's guidance for warm rooms. Some bags are not suitable above a certain room temperature, so check the label.

Cool the room during the day. Close curtains and blinds on the sunny side of the house from mid morning. Open windows once the outside air is cooler than the inside air, which in a heatwave is often not until quite late.

A fan should point away from your baby, not at them. The aim is to move air around the room, not to blow cold air onto a sleeping baby.

Never cover a cot or pram to block light or heat. A cloth or muslin over the top traps heat underneath and restricts airflow. This is one of the more common and more dangerous summer mistakes.

Offer extra feeds. Babies lose more fluid in the heat. Breastfed babies may want to feed more often. Formula fed babies over six months can have cooled boiled water as well.

Check more often than usual. Overheating is harder to judge on a hot night because everyone is warm.

See the Lullaby Trust's guidance on safer sleep in hot weather for more.

Warm the room first, layers second. If the room is consistently below 16°C, the fix is heating, not a fourth layer.

Do not use a hot water bottle or an electric blanket in your baby's cot, and do not use one to warm the cot before bed. Both are unsafe for babies.

Keep the cot away from radiators, and away from draughts from windows and doors.

Follow the bag's guidance for cooler rooms. Use the manufacturer's tog and clothing guidance for your room temperature rather than piling on layers, and do not add blankets over a sleeping bag.

Still no hat. This one catches people out in winter more than any other time of year. The reason for the rule is heat loss through the head, and that reason does not go away because the room is cold.

See the Lullaby Trust's guidance on safer sleep in cold weather for more.

Put two fingers on the skin at the back of their neck, or on their chest under their clothes.

Warm and dry is what you are looking for. That is right.

Hot or sweaty means remove a layer.

Do not judge by hands and feet. They are almost always cooler than the rest of the body and this is completely normal. More parents overdress a baby because of cold hands than for any other reason.

Rapid breathing, unusual restlessness or a heat rash on the neck and chest are all worth acting on. If your baby seems unwell as well as hot, that is a call to 111 rather than a layer to remove.

Short list, and it is worth being strict about all of it.

• •Hats and hoods. Not indoors, not for sleep, not in winter.
• •Loose blankets, duvets and quilts for babies under twelve months.
• •Pillows, until at least twelve months.
• •Cot bumpers, including the mesh and braided kinds.
• •Sleep pods, nests and positioners.
• •Weighted sleeping bags and weighted blankets.
• •Soft toys and comforters.
• •Anything with cords, ties or ribbons, including bibs and pacifier clips.
• •Anything with a hood on it, including hooded babygrows.

The cot should have a firm, flat, waterproof mattress, a fitted sheet, and your baby. That is it.

If you swaddle, use a lightweight cotton or muslin wrap, keep it below shoulder level so it cannot ride up over the face, and leave enough room at the hips for your baby's legs to bend up and out.

A swaddled baby should always be placed on their back.

Stop swaddling as soon as your baby shows any sign of rolling, usually somewhere between three and four months, and sometimes earlier. Do not wait for a confirmed roll. A swaddled baby who rolls onto their front cannot use their arms to lift or reposition their head.

A swaddle counts as a layer. Take it into account when deciding what else your baby wears.

This page draws on the sources below, which we link so you can read them in full. It is not medical advice and it does not replace advice from your midwife, health visitor or GP. If you are worried about your baby, speak to a health professional or call 111.

• NHS, safer sleep and general sleeping bag tog ranges
• NHS, how to dress a newborn baby
• NHS, how to reduce the risk of sudden infant death syndrome
• The Lullaby Trust, how to dress your baby for sleep
• The Lullaby Trust, safer sleep advice
• The Lullaby Trust, hot weather advice
• The Lullaby Trust, cold weather advice

Published by Little Layers. Sources last checked 28 October 2026.

Little Layers is not affiliated with, endorsed by or connected to the NHS or the Lullaby Trust.