I purchased these for myself to use on cold tailgating days. While they do work nicely in a pair of gloves or mittens, I kept mine in the front kangaroo pocket of my hooded sweatshirt.
My mother-in-law liked them so much I have ordered her a set too. She is always cold so may use them for other things- hockey games, for instance, where I would only want gloves.
I am going to buy a lot more of these. They make the icy morning weather a lot more enjoyable. They lasted a long time and kept my jacket pocket toasty. Handwarmers and toe warmers were just the right temperature.