Nope, I use hot hands2, I got a case for Christmas about 5 years ago and I have enough left for many years. Open them shake them up and stick them in my coat pocket before I leave home and by the time I arrive at my hunting spot they are nice and toasty. I take a couple of extra because you never know if you got a dud and you can carry a lot of them without taking up much room in the day pack or pocket. I hate gloves so my hands are in my pockets, warm until I need them. A long time ago I tried electric hunting socks, they were crap, I doubt I would ever use clothing that needs batteries to work again.