Yes, as AAP recommond, sleep sacks are safe for a 6-month-old. At this age, babies are typically more active and have outgrown the need for swaddling. Sleep sacks provide a secure sleep environment, reduce the risk of suffocation from loose bedding, and allow for free movement of arms and legs.
If the sleep sack is sleeveless or the baby's arms are not covered adequately, they may feel chilly, especially in cooler room temperatures. To keep your baby's arms warm, choose a sleep sack with sleeves or add a layer of clothing, such as a long-sleeved onesie, underneath. Monitor their comfort and adjust layers accordingly.
Sleep sacks do not delay development. They provide a safe, cozy sleep environment, reducing suffocation risks from loose blankets. Sleep sacks allow free arm and leg movement while keeping babies warm. Properly fitting sleep sacks do not hinder natural development. Designed with safety and comfort in mind, sleep sacks are recommended sleepwear options.