🌙 Sleep Lab · Pharmacy-Reviewed
Room Temperature for Baby Sleep — What the NHS Actually Says
The ideal nursery temperature, TOG ratings for sleeping bags, and how to spot signs of overheating — based on NHS and Lullaby Trust guidance.
The ideal nursery temperature, TOG ratings for sleeping bags, and how to spot signs of overheating — based on NHS and Lullaby Trust guidance.
Most parents keep their baby too warm. Not out of neglect — out of love. But overheating is an independent risk factor for SIDS. Understanding what the right temperature actually means in practice could be the most important thing on this page.
The NHS and Lullaby Trust recommend keeping a baby's sleep environment at 16–20°C. The ideal is around 18°C. This is cooler than most adults keep their homes — and that is intentional.
Babies regulate body temperature primarily through the head and face — which is why covering a baby's head during sleep is dangerous. In a deeply sleeping baby who is too warm, the arousal response may be suppressed.
Use a room thermometer — not your own sense of warmth. Check the baby's chest or back of the neck — not the hands or feet. A warm chest is comfortable. A sweaty chest means the baby is too hot. Remove a layer.
2.5 TOG + short-sleeved vest = 16–20°C. 1.0 TOG + short-sleeved vest = 20–24°C. 0.5 TOG + short-sleeved vest = above 24°C. Baby sleeping bags remove the risk of loose bedding and allow appropriate layering.
Lullaby Trust · NHS · NICE · Reviewed April 2026.