Slip the SleepSack Swaddle wearable blanket over your baby's regular sleepwear as a replacement to loose blankets in the crib. You may want to put a short or long sleeve bodysuit or a coverall on underneath the wearable blanket depending on your nursery temperature. Don't put your baby to sleep wearing a hat, as this can result in overheating. Secure the swaddle wrap around your baby using the fastener strips. You may choose to use the swaddle feature with arms in or arms out.