Originally Posted By: Treeseeker
I'm not sure I understand. After boiling it starts generating heat immediately? If so, it seems like it wouldn't be much more useful than a hot water bottle. I guess it is an exothermic reaction which would presumably put out more heat than a hot water bottle.

But you can't get heat on demand later as with other hand-warmers.

I still use one of those metal hand-warmers that use lighter fluid that I have had for about 40 years.


No- There is a little disc inside that you have to flex to start the reaction; it does not start immediately.

if i leave them for a few weeks< no problem> if i check in a few months, Most of them are crystallized- not sure if a time issue or a kid issue.... lol. In either case, the plastic melts, the plastic leaks.. nice gimmick, not read for real time....