What should baby wear to bed at 18°C?

The Lullaby Trust gives a babygrow and baby sleep bag as an option for 16–20°C rooms. A babygrow is the same everyday item many parents call a sleepsuit.

The NHS general tog guide places 2.5 tog at 16–20°C. That makes it a useful starting point when you're checking your bag, rather than a rule that every baby at 18°C must wear exactly the same thing.

Find 18°C on the guide for the bag you own. Use its clothing instructions to decide whether a vest belongs underneath the sleepsuit. If the guide gives you a combination, don't automatically add another layer because it's winter.

Check your baby's weight against the bag's minimum and maximum limits. The neck and arm openings must fit so they cannot slip down inside. There should be no additional bedding over a sleeping bag.

See the tog guide for the general NHS ranges and clothing checks.

No. 18°C sits within the 16–20°C range recommended by the NHS and Lullaby Trust. The room feeling cool to you doesn't, by itself, mean your baby needs more clothes.

Feel their chest or the back of their neck under the clothing. If they're hot or sweaty, remove a layer. If their chest feels cold, adjust their clothing or bag using the manufacturer's guidance. Their hands and feet are often cooler and aren't a reliable reason to add warmth.

A room thermometer measures the air. A hand on their chest helps you check how they're managing in the clothes you've chosen. Use both.

Check what happens after the heating goes off. A thermometer that records the minimum temperature can help you find out whether the room stays around 18°C or drops much further.

Don't dress a baby in a warm room for a temperature you think it might reach hours later. Use the current room reading and the bag's guide, then reassess when you check on them or the room changes.

If it falls below 16°C, bring the room back towards 16–20°C where possible. Keep the cot away from a radiator or heater. If your baby feels cold, the Lullaby Trust advises an extra clothing layer or a higher tog bag, rather than blankets on top.

Don't use a hot water bottle or electric blanket in the cot. If you're struggling to keep the room warm, your health visitor can help you work through a suitable plan.

Yes. Light bedding is an alternative to a sleeping bag. The NHS describes a lightweight cellular cotton blanket, tucked in firmly no higher than the shoulders, with your baby's feet at the foot of the cot.

Keep the blanket flat rather than doubled over, and keep their head uncovered. This is an alternative bedding arrangement, not something to add over a sleeping bag.

Don't add layers on age alone. First check whether the sleeping bag is suitable for their weight and size. Some newborns won't yet meet a bag's minimum weight.

If your baby was premature, had a low birthweight or has health needs, follow advice from your midwife, neonatal team or health visitor. A general temperature page can't replace that individual advice.

For the first six months, put your baby to sleep on their back in their own clear, flat sleep space in the same room as you. Keep hats off indoors, including on cold nights.