When I was a teen in the 50's, yes I am dating myself, there weren't electric blankets. I slept upstairs without heat here in the mid-west and it was cold in the winter. We heated river rocks, that were nice and smooth, on the wood stove and wrapped those in old clothes or old flannel sheets and put in the bed under mounds of quilts to help get warm and stay warm. Many a time the cloth that wrapped the rocks would be scorched the next morning. I wonder how close I came to a bed fire? All our quilts had cotton batting as this was before polyester. The GOOD OLD DAYS! Just thought I would share.