From company “Our Cocoon Swaddle Sacks are designed to be both easy to use and difficult to escape from. This zip-up swaddle is TOG rated for warmth to keep a baby snug and securely swaddled without the need for complicated wrapping from day one. Being TOG-rated means that the 0.2 TOG infant swaddle can be used on its own from room temperatures 75℉ + with no blankets in the bassinet or crib to make this a safe sleep option for a newborn or baby. The 0.2 TOG also makes this an ideal summer swaddle for hot weather. To increase warmth, parents can layer up underneath as needed for warmth, and follow our handy FREE room thermometer and what to wear guide included with the product to help them dress their child appropriately.” Size 0-3M