Baby sleeping bags are essential for a good night's sleep. They keep your baby's core temperature stable and are safe for newborns. Pick a thin cotton one for summer, or a thicker padded one for air-conditioned rooms or for winter. Most bags have two-way zippers at the bottom for easy nappy changing. Hypoallergenic snap buttons at the shoulders allow parents to pluck babies out of the sleeping bag easily without disturbing them. All sleeping bags are machine-washable.