← Back to your baby's forecast
What should my baby wear to sleep?
Last verified: July 18, 2026
The short answer: aim for a room at 16 to 20C, dress your baby in no more than one extra layer than you would wear yourself, and use light bedding or a well-fitting baby sleep bag. No hat indoors, no duvet, no weighted blankets. Then trust the check, not the chart: feel your baby’s chest or the back of their neck. Hot or sweaty means remove a layer.
Start with the room, not the outfit
The recommended room temperature for a sleeping baby is 16 to 20C. Keeping the room in that range helps lower the risk of sudden infant death syndrome (SIDS), because the risk is higher in babies who get too hot (The Lullaby Trust: Room temperature).
Guessing a room’s temperature is harder than it sounds, so a simple room thermometer in the room where your baby sleeps takes the uncertainty out of it. And for at least the first 6 months, that room should be the one you are sleeping in too, day and night (Lullaby Trust). Our safe sleep guide covers the full picture.
The one-extra-layer rule
The American Academy of Pediatrics gives the most usable dressing rule there is: in general, dress babies in no more than one extra layer than you would wear yourself in the same room. Layers of clothing are safer than blankets for warmth, and a wearable blanket such as a sleep sack works well, as long as it is the right size and cannot ride up over the head (AAP: Back to Sleep, Tummy to Play).
So if you would sleep comfortably in that room in a t-shirt, your baby likely needs a vest or bodysuit plus one more layer, such as a sleepsuit or a light sleep bag. If you would want a jumper, your baby gets one layer more than that.
Things to skip, from both organisations:
- No hat indoors. Babies keep their body temperature steady by releasing heat through their head, so a hat indoors can make them overheat. The exceptions are the first hours after birth and neonatal care (Lullaby Trust; AAP).
- No duvets or quilts. They trap too much heat and are a covering risk (Lullaby Trust).
- No weighted blankets or weighted clothing, full stop (AAP).
- Keep the head and face uncovered during sleep, always (AAP).
Why there is no exact tog chart
You may have seen charts online matching room temperature to exact clothing and tog values. The Lullaby Trust, the UK’s safer sleep charity, deliberately does not publish one. Their reasoning is honest: the heat trapped between layers changes the warmth of an outfit significantly, and every baby is different, so any chart would promise a precision that does not exist (Lullaby Trust).
That is why the real tool is the check, not the chart.
The hot-or-cold check
Feel your baby’s chest or the back of their neck. Hands and feet are usually cooler than the rest of the body, which is normal and not a sign your baby is cold. If the chest or neck feels hot or sweaty, remove one or more layers (Lullaby Trust). The AAP flags the same signals: a baby may be too hot if they are sweating or their chest feels hot (AAP).
Check when you put them down and again when you would naturally look in on them. It takes two seconds and beats any chart.
Hot summer nights and cold winter ones
When the room will not cool down: follow lighter bedding and lighter clothing, and open the bedroom door and a window if it is safe to do so. Babies also need plenty of fluids in the heat: breastfed babies just feed more often, and formula-fed babies can have a little cooled boiled water as well as their usual feeds (Lullaby Trust; more on that in when can babies drink water).
When the room is colder than 16C: it is rarely necessary to keep the heating on all night. An extra layer of clothing usually solves it. If you do leave the heating on, set it low, no higher than 20C, and keep the cot away from radiators, heaters, and direct sunlight (Lullaby Trust).
When your baby is unwell: a baby with a fever may already be warmer than usual, so resist the urge to wrap them up more. Dress them normally for the room (Lullaby Trust). Our baby fever guide has the exact thresholds for when to call.
When to call your doctor
Overheating worries usually resolve with a layer change, but call your GP or 111 if:
- your baby has a high temperature (see the thresholds in our fever guide)
- your baby is unusually hot and sweaty and removing layers does not settle them
- your baby seems floppy, unusually drowsy, or hard to wake
And the house rule stands: your own concern is reason enough to call.
Keep reading
- Safe baby sleep and reducing the risk of SIDS
- When do babies sleep through the night?
- Baby fever: what counts, what helps, when to call
- Baby sun safety: sunscreen, shade, and staying cool
- All the first-year windows
Sources
- The Lullaby Trust: Room temperature (accessed July 2026)
- AAP: Back to Sleep, Tummy to Play (last updated September 2023)
Peanutbean provides general information for educational purposes only. It is not medical advice. Every baby develops at their own pace. Always talk to your pediatrician about your child’s health.
Common questions
How do I know if my baby is too hot at night?
Feel their chest or the back of their neck, not their hands or feet, which are usually cooler anyway. If the skin feels hot or sweaty, remove a layer of clothing or bedding. Babies who are too hot may also be sweating or have a hot chest.
Should my baby wear a hat to sleep?
No. Babies release heat through their heads to keep their body temperature steady, so a hat indoors can make them overheat. Skip hats indoors except in the first hours after birth or in a neonatal unit, and never let anything cover their head during sleep.
Get a heads-up before the next window
One short email when your baby approaches a new development window. No spam, no daily digests — just the map.
You confirm by email (double opt-in) and can unsubscribe anytime. Details in our privacy policy.
Where is your baby right now?
Two dates, twenty seconds, and you get your baby's personal map of the first year. Free, no signup.
Try the free forecast