I was in Costco this morning. They had boxes of 40 2-packs for $13. I haven't seen them that cheap anywhere else in town.

-40 F is going to be the HIGH TEMP in Fairbanks tomorrow . . .

I have about 6 boxes of those things stockpiled of both the hand and toe warmers. I pick up a box of each every fall.

I have been buying them, both hand and toe warmers for years. They seem to have shelf life though. If you need some for early next fall, you need to buy them in the next month as they won't re-stock and them don't get new ones in until late October or so.

Look at their poly long johns to for $7 top or bottom. They are not as good as the merino wool blend they have carried in the past, but make good base layer for earlier hunting seasons

Yes, do pay some attention to shelf life. I've heard mention of vacuum sealing if one wants to keep them around for an extended period.

Ive had a box for a few years. Still work fine.

IME some of them keep for years and some go bad. Old ones are OK for around camp and cold football games but fresh ones go in my survival kit. I don't stock up on them ahead of time anymore.

Brutal.

Minus 40 F = Minus 40 C - That much I know . . .

what makes them work is high speed rust. All the components for rust are present other than oxygen. that's why when you open the package they activate. the ones that seem to have a shelf life are simply leaking. Buy them on sale, reseal them in Ziploc bags, you'll be fine.
you could even shut them down and restart them by starving them of oxygen.
read the table of contents on them: iron filing, water and a catalyst.

Happened to catch it just right!

Exactly I keep on in my pocket at the weekly trap shoots. Reseal in a ziplock press out the air, and you can get several uses from one. I hate to wear a glove on my shooting hand,and these keep the fingers working.

I use the old Jon-E handwarmers. My kids can't believe I carry fire in my pocket. I mainly do it for nostalgia. They work pretty good though!

Doesn't sound like much fun.

Yeah, i have about half a dozen of those. They do get hotter than the disposables, but the "scentless" fluid ain't, and it is getting hard to find locally. Only place i CAN find it is online, and the cost works out about the same per use.
You can use lighter fluid in them, but they will smell like that forever more.
I use them only for football games, and parades, where the smell doesn't matter, and the added wieght makes no difference.
I'm actually thinking the best use for them would be a heated scent dish for doe scent.

I have one that has a little metal doe face with a compartment for a sponge. I guess you soak the sponge with doe scent. The contraption clips onto the side of the handwarmer.

Sounds abit like a therocell.
Me, i have a few magnetic Parts dishes. the hand warmers Lock Tight to the bottom. A donut of Cheap styrofoam A little spray paint, And you have a heated scent dispenser

Had 1 weekend at lease this year,they would have been handy

I've got a pair of Zippo hand warmers. They smell like lighter fluid while burning, but crank out the heat.