Husband tried one at a friend’s house while recovering from a torn side muscle. He said that the bag’s size and shape did the job much better than his electric heating pad (which we sadly left at home.)
I decided to make him one but improve the design a little bit by making chambers so the heated contents wouldn’t slip away from the part of his body that needed the heat. By using a kitchen towel for my project he can also use it as a homemade moist heating pad if he likes.
Toasty warm!