Room temperature and what to wear

Updated 24 October 2026 · Written by the Lullsong team. General information, not medical advice.

Why overheating matters

The risk of sudden infant death is higher in babies who get too hot (The Lullaby Trust; AAP, 2022). Babies can’t take off a layer themselves, so the room and their clothing need to do it for them.

How to check

• Use a room thermometer. Guessing the temperature is unreliable.
• Feel your baby’s chest or the back of the neck. Sweating, a hot chest or flushed skin mean your baby is too warm.
• Dress your baby in no more than one layer more than you would wear in the same room.

Hot nights

• Take off layers. A vest or nappy alone can be enough.
• Close blinds or curtains during the day.
• A fan can cool the room. Keep it out of reach and don’t point it at your baby.
• Don’t cover a pram or buggy with a blanket: it traps heat.

Cold nights

• Add a layer or use a warmer sleep bag rather than loose blankets.
• No hats indoors once you are home from the hospital.

More on the basics: safe sleep: the essentials.

Sources

1. The Lullaby Trust. Room temperature: safer sleep information. Accessed 24 October 2026. https://www.lullabytrust.org.uk/baby-safety/safer-sleep-information/room-temperature/
2. Moon RY, Carlin RF, Hand I; AAP Task Force on SIDS. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics 2022;150:e2022057990. https://doi.org/10.1542/peds.2022-057990

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• The 4-month sleep regression: what’s actually known
• Wake windows: what the research actually says
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• When to stop swaddling
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