Comforters were all filled with cotton at that time. They were kinda heavy especially some nights we needed more than one layer.
Three layers of cotton comforters can make it hard for breathing. Yet in order to keep the cold air outside, the two sides of the comforters must be tucked under the person.
My parents used to tuck them tightly for me, made me into a spring roll. Then they would stuff soft clothes around my neck and foot.
However I sometimes woke up freezing: flipping around made the roll loose.
Sleeping in the same position and keeping the wrapper tight all night was considered as “good sleeping manner”. Some people can really do that while I cannot.