The Magic Sleepsuit is to be used in the bare crib for back sleeping only. It should be used in a room at the recommended temperature for babies. It is not recommended for co-sleeping, or with any sleep positioners. You use the Magic Sleepsuit the same way you would a traditional sleeper. You simply place the baby in the suit and zip it up. Depending on the room temperature and the heat regulation of the baby, you can place the baby in the suit with a diaper only, a cotton onesie, or in a traditional cotton one piece sleeper. We recommend no more than one layer of light cotton for breathability. The Magic Sleepsuit is constructed with two zippers to allow easy placement of the baby in the suit and easy diaper changes. The feet and hands are open for movement and ventilation. Like with any baby sleep product, it is up to the parent or caregiver to monitor the baby in the Magic Sleepsuit and make sure the baby's room is at the recommended room temperature for babies. They are responsible to make sure that the baby does not overheat. Please see the Safety page for links to websites with information on safe sleep tips for babies.