There's no single worldwide answer to "what temperature should a baby's room be?", because the main safe-sleep bodies don't agree on a number. The Lullaby Trust and the NHS in the UK suggest 16–20°C (61–68°F). Red Nose in Australia doesn't set a figure and says to dress your baby for whatever the room is. The AAP and NICHD in the US don't give a number either, but stress that a baby who gets too hot is at higher risk of sudden infant death syndrome (SIDS). All of them agree on the practical part: dress your baby for the room, keep their head uncovered, and check how warm they feel rather than trusting the thermostat.
What temperature should a baby's room be?
| Authority | Room temperature position |
|---|---|
| Lullaby Trust (UK) | 16–20°C, with a room thermometer |
| NHS (UK) | About 16–20°C |
| Red Nose (Australia) | No single right temperature; dress for the room |
| AAP (US) | No figure; avoid overheating |
| NICHD (US) | No figure; a hot room is linked to SIDS |
UK. The Lullaby Trust says the recommended room temperature for babies is 16–20°C "so that they don't get too hot", and that light bedding or a lightweight, well-fitting sleeping bag is comfortable in that range. The NHS SIDS page also suggests about 16–20°C, checked with a room thermometer.
Australia. Red Nose says it doesn't recommend a specific room temperature for sleep. Instead, it says to dress your baby as you would dress yourself for the temperature of the room. Its summer advice puts it plainly: there is no single "right" room temperature.
US. The AAP's safe sleep guide says overheating can increase the risk of SIDS and suggests dressing your baby in only one layer more than you're wearing. The NICHD Safe to Sleep FAQ says overheating from too much clothing or too many blankets and a high room temperature are associated with a higher SIDS risk, without giving a figure.
So if you live in the UK, aim for 16–20°C. Elsewhere, the UK range is a reasonable reference point, but how your baby feels is what counts. A room of 22°C on a summer night isn't dangerous in itself; it simply means fewer layers, as the next table shows.
What should my baby wear at different room temperatures?
The Lullaby Trust's easy-read dressing card is one of the few sources that links outfits to a room temperature. It stresses that every baby is different and the ranges are a guide only.
| Room | What the Lullaby Trust suggests |
|---|---|
| Cooler than 16°C | Extra clothing layer or higher-tog bag; no blanket on a bag |
| 16–20°C | Sleepsuit and sleeping bag, or sleepsuit and tucked light blanket |
| Warmer than 20°C | Short-sleeved bodysuit, or just a nappy |
| Much warmer, very hot | Short-sleeved vest, or just a nappy |
The card also warns that even when it's cooler than 16°C, it's possible to wrap a baby up so warmly that they overheat. Dressing your baby for sleep covers sleepsuits, sleeping bag fit, blankets and hats in more detail.
Do I need a room thermometer?
Sources differ. The Lullaby Trust says to use a room thermometer in the rooms where your baby sleeps, because temperature is hard to guess. Red Nose in Australia says it doesn't believe a room temperature monitor is necessary.
A cheap thermometer can be handy if you tend to overheat the house in winter or you're not sure how warm the room gets overnight. Use it as a prompt, not a target: a room reading of 18°C doesn't tell you whether your baby is wearing too much.
What tog sleeping bag should I use?
No safe-sleep body publishes a tog-by-temperature chart. The Lullaby Trust says it can't give that advice because fabrics insulate differently, layers trap heat differently and every baby is different. Red Nose in Australia says to choose a tog that suits the room temperature, following the manufacturer's guide: a lower tog for warmer weather and a higher tog for cooler nights.
In practice:
- Check the room temperature, or how warm the room feels to you.
- Use your sleeping bag maker's chart to pick the tog and what to wear underneath.
- After your baby has settled, feel their chest, back of the neck or tummy.
- Adjust the layer underneath next time, rather than adding a blanket over the bag. The Lullaby Trust's cold-weather advice says not to put blankets on top of a sleeping bag.
Can I use a heater, fan or air-conditioning in my baby's room?
Heaters. You often don't need one overnight. The Lullaby Trust says it's rarely necessary to keep the heating on all night, and if you do, to keep it low, no higher than 20°C. Red Nose in Australia says heating or cooling doesn't need to run all night. If you use a portable heater, the Lullaby Trust says to point it away from your baby, and both it and the NHS say to keep the cot away from radiators, heaters, fires and direct sunlight.
Never in the cot. The NHS says never to let your baby sleep with a hot water bottle or electric blanket. Red Nose's bedding advice in Australia says never to use electric blankets, wheat bags or hot water bottles for babies, and the Lullaby Trust says no hot water bottles in any baby sleep space, including an adult bed.
Fans. A fan can help move air around a warm room. The Lullaby Trust says not to aim it directly at your baby, and Red Nose in Australia says to keep it pointing away from your baby while it circulates air. The AAP's extreme heat advice says fans may help if you have no air-conditioning, but not to direct the airflow at yourself when the room is hotter than about 32°C (90°F), because dry blowing air can raise the risk of dehydration.
Air-conditioning. Cooling a hot room is fine. Red Nose says you don't need to leave it on all night. Many families find it helps to keep the cot out of the direct stream of cold air and to dress their baby for the temperature the room will settle at overnight.
How do I keep my baby's room cool on a hot night?
The Lullaby Trust's hot-weather advice suggests:
- keeping curtains or blinds closed during the day so the room doesn't heat up
- opening the door and a window at night if it's safe
- using a fan that isn't pointed at your baby
- lighter bedding and clothing, with fewer layers and a lighter sleeping bag
- a short-sleeved vest or just a nappy in very hot weather
- checking your baby regularly by feeling their chest or back of the neck
Red Nose adds light natural fabrics such as cotton or bamboo, a low-tog bag for summer, and keeping the head and face uncovered. In extreme heat, the AAP says that if your home has no air-conditioning, find a nearby building that does. Offer feeds more often too: Red Nose says babies need to drink more frequently in hot weather. Hot weather covers feeds, water by age and heat illness.
How do I keep my baby warm on a cold night?
Warm your baby with clothing, not heat sources. The Lullaby Trust's cold-weather advice is to:
- add an extra layer of clothing or choose a higher-tog sleeping bag if your baby seems cold
- use lightweight sheets or blankets, not thick, fleecy or padded blankets or duvets, if you don't use a bag
- tuck blankets in firmly, no higher than the shoulders, with your baby's feet at the foot of the cot
- count a blanket folded double as two layers
- take hats off indoors, because babies lose heat through their heads
The Lullaby Trust also notes that babies are safer slightly cool than too hot. Cool hands and feet are normal on a cold night.
How can I tell if my baby is too hot or too cold?
Red Nose in Australia says to feel your baby's tummy, which should feel warm; the NHS and the Lullaby Trust say to feel the chest or the back of the neck. Cool hands and feet are normal.
| What you notice | Likely meaning | What to do |
|---|---|---|
| Warm, dry chest, neck or tummy | Comfortable | Nothing |
| Hot, sweaty or clammy body, damp hair | Too hot | Remove a layer; cool the room |
| Flushed cheeks or heat rash | Too hot | Remove layers; offer a feed |
| Cool tummy or chest | A bit cold | Add a light layer of clothing |
| Cold to touch and shivery | Too cold, possibly unwell | Call your local emergency number (000 in Australia, 999 in the UK, 911 in the US) now |
NICHD lists sweating and a chest that feels hot to the touch as signs a baby is too hot, and the AAP's swaddling page adds damp hair, flushed cheeks, heat rash and fast breathing. Red Nose's summer advice describes heat stress as unusual fussiness, listlessness or irritability, and pale, clammy skin that becomes hot and flushed. If your baby is listless, floppy or breathing very fast, don't just remove a layer: call your local emergency number (000 in Australia, 999 in the UK, 911 in the US). Baby sweating at night explains what to do about a sweaty sleeper.
When to get help
These are on the NHS list of when to get urgent help, which also includes skin that feels cold or damp (clammy) and a temperature of 39°C (102.2°F) or higher at 3 to 6 months. If a thermometer reads below 36°C, the NHS says to check twice more within 10 minutes. See fever in babies.
Get medical help today (same-day GP, after-hours doctor or a health advice line (Pregnancy, Birth and Baby on 1800 882 436 in Australia, NHS 111 in the UK, your pediatrician's after-hours line in the US)) if your baby still feels hot after you've removed layers and cooled the room and seems unwell, or is feeding much less than usual in hot weather.
Talk to your GP or child-health nurse if you're unsure how to keep your home warm or cool enough, especially if your baby was premature or has a health condition.
