TL;DR
Keep your baby’s room between 16 and 20°C, the NHS-recommended range. Use the chart below to match the right vest, sleepsuit and sleeping bag TOG to the temperature in the room tonight. Always confirm by feeling your baby’s chest or the back of their neck, never their hands or feet.
Getting the night-time layers right is a common worry for new UK parents. Too hot and your baby is at higher risk, too cold and they will be unsettled and wake more. This guide gives you the NHS and Lullaby Trust advice on room temperature plus a clean chart for exactly what your baby should wear to sleep safely.
The chart is the part to bookmark. The rest of the article explains how to check whether your baby is comfortable, what to do in hot and cold weather, and the warning signs that need NHS 111 or 999.
The NHS-recommended baby room temperature is 16 to 20°C
The ideal room temperature for a sleeping baby is between 16°C and 20°C. This range helps reduce the risk of sudden infant death syndrome (SIDS). It often feels cool to adults, so a reliable room thermometer is worth having in the nursery. Overheating is a known SIDS risk factor, so when in doubt, lean slightly cool rather than warm.
Quick Fact
The NHS and Lullaby Trust recommend a baby’s sleep room sit between 16 °C and 20 °C, all year round.
Baby sleep temperature chart for UK rooms
Use this chart as a starting point. Always confirm by feeling your baby’s chest or the back of their neck. Every baby regulates heat slightly differently.
| Room Temperature | Feels Like | What Baby Should Wear | Sleeping Bag TOG |
|---|---|---|---|
| 27 °C and above (Heatwave) | Hot 🥵 | Nappy only, or nappy + short sleeve vest | 0.2 to 0.5 TOG (optional) |
| 24 to 26 °C (Very warm) | Warm 🌞 | Short sleeve vest | 0.5 TOG |
| 21 to 23 °C (Warm room) | Mild ☀️ | Short or long sleeve vest | 1.0 TOG |
| 18 to 20 °C (Typical UK home — NHS IDEAL) | Just right ✅ | Long sleeve vest + sleepsuit | 1.0 to 2.5 TOG |
| 16 to 17 °C (Cool winter) | Cool 🌧️ | Vest + long sleeve sleepsuit | 2.5 TOG |
| 14 to 15 °C (Cold, older home) | Cold ❄️ | Vest + sleepsuit + thin cellular blanket OR move to 3.5 TOG | 2.5 TOG (or 3.5 TOG, NOT for newborns under 3 months) |
Important notes:
- Newborns under 1 month: start a layer lighter and add a thin layer underneath rather than going to a high TOG.
- No hats indoors during sleep.
- No duvets, quilts or pillows for babies under 12 months.
- No weighted sleep sacks (Lullaby Trust warning).
What is a TOG rating? Quick explainer
TOG stands for Thermal Overall Grade. It measures how warm a piece of bedding or clothing is. The higher the number, the warmer the fabric. Lower TOG bags are for warm rooms, higher TOG bags are for cold rooms.
1. Low TOG, 0.2 to 1.0
For warm rooms 21°C and above. Used in summer and warmer modern UK homes.
2. Mid TOG, 1.0 to 2.5
For most of the year, rooms 16°C to 21°C. The everyday default for many UK families.
3. High TOG, 3.5
For cold rooms under 16°C, typically older UK homes in winter. Not recommended for newborns under 3 months.
How to actually check if your baby is too hot or too cold
Place your hand on your baby’s chest or the back of their neck. Their hands and feet will often feel cooler than the rest of their body, which is completely normal and not a sign they are cold. Two simple rules:
- Too hot: chest feels hot or sweaty. Remove a layer.
- Too cold: chest feels cold to the touch and baby may look pale. Add a layer.
Never let your baby sleep in a hat indoors. Hats trap heat at the head, which is how babies lose excess heat. Hats indoors at sleep time are a recognised SIDS risk.
✅ Where to check
- Chest (skin under sleepsuit)
- Back of neck
❌ Where NOT to rely on
- Hands (always feel cooler)
- Feet (always feel cooler)
Hot weather sleep safety during UK heatwaves
UK summers are getting hotter, 2022, 2023 and 2024 all set new records. During a heatwave, prioritise keeping the room cool.
- Open windows and use a fan to circulate air, never pointed directly at the cot.
- Close blinds during the day to keep the sun out.
- Drape a damp muslin cloth over the cot rail to cool the air gently.
- Move baby to the coolest room in the house if needed.
- Breastfed babies may want to feed more often. Formula-fed babies over 6 months can be offered small sips of cooled boiled water.
- Strip the layers back to nappy + vest, or just nappy, if room temperature climbs above 27°C.
Cold weather sleep safety
- If chest or back of neck feels cool, add a vest under the sleepsuit.
- Use a correctly-sized sleeping bag so baby cannot slip down inside.
- If using blankets instead of a sleep bag, place baby feet-to-foot of cot, blankets tucked in firmly, no higher than shoulders.
- Never add a duvet, quilt or pillow for babies under 12 months.
- Avoid heating spikes by an electric blanket or radiator next to the cot.
When to call NHS 111 or 999
🚨 Get help if:
- Baby is hot, sweaty and unsettled after layers are removed, call NHS 111.
- Baby is cold, pale or mottled and does not warm up after adding a layer, call NHS 111.
- Any baby under 3 months with a temperature of 38°C or higher needs urgent advice. Call 111 or attend A&E.
- Any baby 3 to 6 months with a temperature of 39°C or higher needs urgent advice.
- Baby is unresponsive, very floppy or struggling to breathe, call 999 immediately.
Frequently Asked Questions
How long should my baby sleep in my room?
The NHS recommends your baby sleeps in the same room as you for all sleep, day and night, for at least the first 6 months. This includes nap times. The safest setup is your baby in their own clear flat cot or bedside crib, next to your bed, on their back.
Can my baby sleep in a car seat overnight?
No. Car seats are for travel only. Extended sleep in a car seat can cause baby’s head to slump forward, which risks airway obstruction. If you arrive home with a sleeping baby, move them to their cot as soon as you can, even if it disturbs them.
Are weighted sleep sacks safe?
No. The Lullaby Trust specifically advises against weighted sleep sacks, sleep pods and baby nests. Use a standard, well-fitting baby sleeping bag with a TOG appropriate for the room temperature.
What if my baby kicks off blankets at night?
A baby sleeping bag is the simple fix. It stays on all night, provides consistent warmth, and removes the risk of loose bedding covering the face. For most UK families a 1.0 TOG bag for most of the year and a 2.5 TOG for winter covers it.
Should I put socks or a hat on baby for sleep?
No hats indoors during sleep, ever. Socks are usually not needed if the room is in the right temperature range and the sleeping bag is the right TOG. If feet are persistently cold and chest is comfortable, a pair of light cotton socks is fine.
The Bottom Line
Keep the room at 16 to 20°C. Use the chart to pick the right vest, sleepsuit and sleeping bag TOG. Check baby’s chest or back of neck, never their hands.
Trust the chart as a starting point, but trust your baby’s body more. A baby who is sweaty across the chest is too hot. A baby who is cold across the chest needs a layer. Everything else is detail.
Related reading: UTI Home Remedies · Protein for Women Over 45 · NHS Menopause Check 2026
Read the Lullaby Trust safer sleep guidance
The full UK safer-sleep evidence base, updated for 2026, in one official place.
