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Yes, sleep sacks are actually considered a safer alternative to loose blankets in the sleep space. The AAP recommends keeping soft objects and loose bedding out of the crib, and a wearable blanket like the Sleepy Bag keeps babies cozy and contained without that risk. Our Sleepy Bag is designed with a fully encased zipper and seams to protect delicate skin, and a double zipper for easy diaper changes. One important note: do not size up. A proper fit around the arms and neck is essential for safe use, so always check the fit before putting your baby down to sleep. For a full breakdown of sizing by weight and height, head to this guide.

Sleep sacks can be used from birth and are a great next step once your baby starts showing signs of rolling out of a swaddle. If they're squirming free or starting to turn over, that's your cue to start introducing a sleep sack during naps and eventually overnight. Unlike a swaddle, a sleep sack leaves arms free and gives little legs room to kick and move. The Sleepy Bag comes in three TOG ratings to match your nursery temperature year-round: Lightweight (0.5 TOG) for 74°–78°F, Seasonless (1.5 TOG) for 68°–74°F, and Winter Weight (2.5 TOG) for 61°–67°F. Learn more about TOG ratings here.

Fit is everything when it comes to safe sleep. The neck and armhole openings should be snug enough that baby can't slip inside, but never tight or restrictive. Armholes should allow free movement without gaping, and the body should have plenty of room for kicking and wiggling. If you notice the armholes are too snug or the zipper is hard to close, it's time to size up. But if the bag just looks long, that's totally normal and by design. Do not size up just to get more wear out of it — an oversized neck or armhole isn't safe. For a full breakdown of sizing by weight and height, head to this guide.