What to Dress Baby in at Night

This is the single most useful thing to know, and it is the thing most people get backwards.

What your baby wears at night should be based on the temperature of the room they are sleeping in. Not the temperature outside, not the season, not what the weather app said this afternoon. A bedroom in a well insulated new build might sit at 21°C in February. A back bedroom in a Victorian terrace might drop to 15°C in October. The month on the calendar tells you almost nothing.

So the first thing to buy, if you have not already, is a room thermometer. They cost a few pounds. Put it near the cot, at roughly cot height, away from a radiator and away from a window. Check it when you put your baby down.

The Lullaby Trust recommends keeping the room your baby sleeps in between 16°C and 20°C. That is the target. If your room sits outside that range, the better answer is usually to change the room, by opening a window or adjusting the heating, rather than to keep piling on or stripping off layers.

The outside forecast still matters, but for a different reason. It tells you which way the room is going to move overnight. More on that further down.

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.

Link this section to the specific NHS page on dressing a newborn, not the NHS homepage. Deep links are worth more, and a reader who follows one and lands on the exact guidance you described trusts the next thing you tell them.

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. A well fitted sleeping bag is the simplest way to keep bedding secure. If you use blankets instead, they should be tucked in firmly no higher than your baby's shoulders, with your baby's feet at the foot of the cot so they cannot wriggle down underneath.
• Sleeping bag fit. The neck and armholes should be snug enough that your baby cannot slip down inside the bag. No hoods.

Their guidance on dressing your baby for sleep is the most detailed free resource on this topic in the UK, and it is the source our own recommendations are built around.

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.

Most UK families get through the whole year with three bags:

• 0.5 tog for summer and warm rooms
• 1.0 tog for spring and autumn, and for warm houses in winter
• 2.5 tog for cold rooms and most of the winter

You should not need anything warmer than a 2.5 tog. If a 2.5 tog with a sleepsuit and a long sleeve vest underneath is not keeping your baby comfortable, the room is too cold. Warm the room rather than adding insulation.

The thing nobody explains about tog. The rating assumes a specific base layer underneath. A 2.5 tog bag over a vest and a sleepsuit is meaningfully warmer than the same bag over a vest alone. When you add a layer underneath, you are effectively moving up the scale. This is why the chart above works the other way round. You start from the bag you own, and it tells you what goes underneath.

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.

You are not dressing your baby for the temperature at bedtime. You are dressing them for four in the morning.

UK bedrooms cool overnight, and older housing stock cools faster. If your heating goes off at eleven, the room will keep dropping until the sun comes up or the heating comes back on, and the coldest point of the night is usually somewhere between three and five.

Two practical approaches.

If your heating runs overnight, or your home holds its temperature well, dress for the reading on the thermometer at bedtime. The room is not going to move much.

If your heating goes off, check the thermometer at bedtime and then think about where the room is heading. If tonight's forecast low is well below last night's, the room will follow. Dressing one band cooler on the chart than the bedtime reading suggests is a reasonable adjustment. Adding a base layer is easier to correct than swapping a sleeping bag at three in the morning.

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.

At 24 to 25°C, a short sleeve vest under a 0.5 or 1.0 tog. At 26 to 27°C, a short sleeve vest under a 0.5 tog, or just a nappy under a 1.0 tog. At 28 to 29°C, just a nappy under a 0.5 tog and nothing heavier. At 30°C and above, no sleeping bag at all.

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.

Sleepsuit, long sleeve vest, 2.5 tog. That combination covers every UK night below 18°C. If it genuinely is not enough, the room is too cold and needs warming, not another layer.

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, damp or clammy means too many layers. Take one off. Damp hair at the back of the head and flushed cheeks are the other signs.

Cool to the touch on the chest or neck means they could use one more 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, for babies under six months. After that, a small comforter is generally considered fine, and many children settle better with one.
• •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. Factor it into the chart above rather than adding it on top.

Every recommendation on this page follows published guidance from the sources below. 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, 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. Last reviewed 20 August 2026 against current NHS and Lullaby Trust guidance. Next review due February 2027.

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