It wraps around the ankles for outstanding heat retention. A comfortable fit hot innerwear that protects against the cold of the winter. Once you put it on, you may not want to take it off for too much warmth. The cold is from your feet, so the back of these spats have a brushed feel that is very warm. Just like a blanket. Warmth you cant keep it going? Not good for saving energy on air conditioners and heaters?