A 1 TOG sleeping bag is suitable for a room temperature of around 75 - 81 °F or 24 - 27 °C. If the room is on the warmer side of this temperature range your can dress your little one in a short-sleeved one-piece under their sleep bag. If the room temperature is on the colder side of this range, you can dress your little one in a long-sleeved one-piece.