The Cocoon Swaddle Sack promises safe and snug sleep, all winter long. The 3.5 TOG Willow swaddle sack provides warmth without overheating, giving parents peace of mind. Crafted from soft, breathable materials, the swaddle helps regulate baby's temperature. It also allows for natural movement while preventing startle reflex. This clever design transitions effortlessly from a swaddle to a sleep sack as the baby grows.