Worrying whether your baby is too hot or too cold is one of those constant new-parent questions — their hands always feel cool, and they can’t tell you what they need. The reassuring part: babies are easy to read once you know where to check, and a simple layers approach handles almost everything. It’s worth getting roughly right, though, because overheating is linked to a higher risk of SIDS — so a little care matters. Here’s how to tell, how to dress them, and what to do in hot and cold weather.
How to tell
Don’t go by their hands and feet — those are normally cooler, even when your baby is perfectly warm. Instead, feel the chest, tummy, or the back of the neck: it should feel comfortably warm, not hot and clammy or cold.
Signs your baby is too hot: sweating, damp hair, flushed cheeks, faster breathing, or a heat rash. Too cold is much rarer indoors with a few layers on, and would show as a cold chest or tummy.
The layers rule
Dress your baby in layers you can add or remove, rather than one thick item. A simple guide: dress them in about one more light layer than you’re comfortable in. Choose natural, breathable fabrics, and adjust through the day as the temperature changes.
| Situation | What to do |
|---|---|
| Check if too hot or cold | Feel the chest or back of the neck, not the hands or feet |
| Dressing | Layers — about one more light layer than you’re wearing |
| Sleep room | Around 16–20°C, a sleeping bag, no hat indoors |
| Car seat | Thin layers under the harness; a coat or blanket over the top |
| Hot weather | Shade, light clothing, extra feeds, a cool room |
Room temperature for sleep
For the room where your baby sleeps, aim for around 16–20°C, and a room thermometer makes it easy to check. Use a safe sleep setup — a baby sleeping bag suited to the temperature rather than loose bedding, no hat indoors, and the cot away from radiators and direct sun. Remember that a sleeping bag is warmer than it looks, so factor it in rather than adding lots underneath.
Hot weather
Keep babies under six months out of direct sun, use shade, and dress them in light, loose clothing — sometimes just a vest and nappy is plenty. Offer more frequent feeds, as babies can become dehydrated in the heat, keep the room cool (a fan helps, but not pointed directly at them; close curtains during the day), and watch for the overheating signs above. Never drape a blanket over the pram to shade it — it traps heat fast; use a proper sun shade that lets air through, as in going out with your baby. A cool flannel or a tepid bath can help on a very hot day.
Cold weather
Outdoors, add a hat and an outer layer over their usual clothes — but take the coat and hat off again once you come indoors or into a warm car, so they don’t overheat. The important safety point: don’t put a thick coat under a car-seat harness. A padded coat squashes down in a crash and leaves the straps too loose to hold your baby. Instead, dress them in thin layers, buckle the harness snugly, and tuck a coat or blanket over the top.
Hot, or actually a fever?
If your baby feels hot, cool them down first — remove a layer, cool the room — and check again. A genuine fever is different: a temperature of 38°C or higher in a baby under three months is always urgent and needs prompt medical help, as covered in the red flags. A thermometer settles the question quickly.
The short version
Check the chest, not the hands; dress in adjustable layers (about one more than you’re wearing); keep the sleep room around 16–20°C without overheating; adapt to the weather; and never bulk your baby up under a car-seat harness. Get those right and your baby will be comfortable in almost any conditions — and you’ll have one less thing to second-guess at 3am.
This is general information, not medical advice. For concerns about your baby’s temperature, overheating, or a fever, follow the advice of your midwife, health visitor, or doctor, and your local safe-sleep guidance.