Sleep sacks, or wearable blankets, are safe for babies and are a great way to keep a baby warm as long as they are appropriately sized. Sleep consultant Dr. Aubrie DeBear, PsyD., tells Verywell Family that parents should “ensure your child is wearing the correct size and that the sack is not too small or large, which can lead to rising up to cover the face, or inhibiting full movement.” To do this, she says parents should “check the age and weight specifications of the sleep sack to make sure it's the right fit for your child.” In order to create a safe sleeping environment and reduce the risk of SIDS, parents should follow the Safe Sleep Guidelines from the American Academy of Pediatrics (AAP). Babies should sleep in their own crib with a firm mattress free of soft objects and loose bedding like blankets, pillows, toys, or anything else that could cause suffocation. Additionally, it is important to note that the AAP strictly advises against the use of weighted sleep sacks or blankets for babies.