This is such a cute and practical thing to own! I get cold hands very fast, even when it's pretty warm outside, something to do with bad circulation of blood to my extremities or something...But I started using hand warmers a few years ago and am very happy with the result.
This one I got as a Xmas gift for myself and I've been using it ever since it arrived.
It is indeed very easy to reuse, just like the instructions say, and the cover has a very cute design to it, the texture is soft and it is easy to wash after it gets dirty.
I plan on getting a second one soon, to give as a gift to one of my friends.
I recommend it not only for kids!:D