Tried these out this morning - was wondering how they'd fare against the disposable ones in terms of heat, longevity, etc.
I give them a hearty and enthusiastic "Meh"
Just not really impressed. They're 20 bucks apiece. At first I just bought one thinking it would be all super hot and I could transfer it from hand to hand, then decided just to go ahead and try a second one from the start - bought them two weeks and 40 miles apart, different colors even, so the likelihood that their identical performance was representative is pretty good.
I just never could get them to do anything impressive. Putting skin to bare metal was almost instantly uncomfortable, but with them in the velvet pouch they just never gave good heat - subpar to the disposables I thought. They're super big and bulky in gloves. they're a lot bigger than they look - closer to a deck of cards than a Zippo lighter. They take a long time to light, it's hard to get them lit, and there's no instant feedback to whether they're actually "lit" or not since they're flameless. You pretty much just have to hang on to it for a minute and see if it's warm.
All in all, I prefer disposables. And lighter fluid is a pretty specific thing. It took the better part of half a bottle to fill two (and once you light them you can't put them out). I can't imagine a time when I would have burned through hundreds of disposable hand warmers but have a large enough quantity of lighter fluid to keep them viable.
I haven't studied on it, but if there's a substitute (kerosene?) that you can put in there, they might be viable for when all the disposable ones are used up.
Hothands are being clearanced out for the season at Walmart for $5. All else being equal I'd rather have 8 packs of those for my $40