Yeah your butt should get warm. They work great. It's 25 degrees here this morning in New Jersey so I definately use them!

I find it wierd that when you turn it on at first, theres 2 lights lit up. After a while I guess they get hot and then it goes to 1 light. I assume that happens to everyone too? Sometimes its annoying because I'm cold and I wish it would just stay on 2 until I change it to 1 myself.