A baby or toddler cannot yet do this by itself. In particular, a room that is too warm is not advisable and can even be dangerous. A baby soon overheats. The bedroom temperature for a baby is better to be a little on the low side than too high. Even if it feels too cold to you, the ideal temperature for a nice nap is 18-20 °C during the first months. From two months onwards, this may be a degree lower: 16-18 °C.