Why is the SleepSack Swaddle sleeveless? December 18, 2024 20:19 Updated It is sleeveless to reduce the chance of baby overheating and is easier to be worn with regular sleepwear underneath. Related articles Can I start using a larger-sized SleepSack Swaddle on my newborn and then he/she can just grow into it? How does the SleepSack Swaddle help babies sleep safely? When should I stop swaddling my baby? What is a TOG Value? How do I use the SleepSack Swaddle?