Well these are interesting. How long, after boil, will they hold their ability to be reactivated? I’m reading it as I could use one today, boil it, then click it again 10 months from now?
I have these! I think they last forever… I’m not sure though.
Basically, yes. I bought some of these about two years ago, and I have done exactly that. If you just leave it alone after boiling it, it will be ready to use indefinitely. You can potentially activate them inadvertently if they take a sudden impact, but that’s about it.
How long do they give off heat once activated?
On a cold day? About 30 minutes. Which is perfect for me because that’s about how long it takes me to get to work on the bus.
Sometimes I bring an extra un-activated one with me to the office and I use it for the bus ride back.
It’s good for TMJ. Not likely you’d need 20, but cool for stocking stuffers for next Christmas!