Swaddling an infant during “meltdowns” and for sleep is a way to position baby for calming and organizing her central nervous system. The blanket provides comfort and gives stability to all sides of the body which helps baby calm over time.
When swaddling, be sure to allow baby’s hands to stay close to her face and mouth for the special comfort provided by sucking and hands to midline positioning. Sucking and bringing her hands together at the chest, or midline, is very calming for the brain. See Sucking is Supreme and Magic of Midline.
Swaddling is a good sleep strategy until baby is about 5 months old. Around that time, infants become more mobile and it is time to stop confining her in a swaddle for sleep.
“Because every baby is unique and because no blanket can naturally regulate a baby’s temperature, it is important for caregivers to dress their baby based on the current temperature of the room and their unique baby.
The American Academy of Pediatrics recommends dressing the baby in no more than one more layer than you are wearing to be comfortable in the same environment. It’s important not to overdress baby for sleep.
Signs of overheating include sweaty back or neck, damp hair, rapid breathing or heat rash. If baby feels sweaty, remove a layer of clothing. Sometimes baby’s hands or feet feel cool due to their immature blood circulation which is considered okay as long as their chest, tummy and back are warm, not sweaty or cool.”