These are quite comfortable but my only problem with them is that they only heat the bottoms of the feet. The ingredients inside the slippers is in a bag at the bottoms. Unfortunately, the part of my feet that get cold are the tops. If you put the bottom of one foot on top of the other this helps but is not as effective as if the heating granules were evenly distributed throughout. Heats fast in a microwave and is soothing if your situation is different than mine.