I had a pair of these before. They are awesome! If these are the same as the one that I had I don't think you put the slippers in the microwave...you put the inserts in. They slip under an opening in the bottom of the slipper. It's totally away from your feet. It's in between the material of the slipper. That's way they are reusable and washable...the insert comes out for you to wash the slipper. I am going to bid...I hope I win. I lost one of my slippers in my last move. Yeah!