if the hand warmer is labeled as being good for 7 hours but I only use it for 1 hour on my ride to work this morning - can I wrap it in plastic (depriving it of air) for 8 hours and then use it again for another hour for my trip home tonight?

Yes, stick it in a ziplock and suck all the air out.

ok??? let us know how this actually worked out.

the type I like are the rechargeable type. boil in water after use to split the chemicals back into their parts and reuse. those that are oxygen dependent are not rechargeable.

it's in 2 bags now and when I checked before they didn't feel warm at all (through the bags). I didn't suck on the bags but they're pretty much void of air spaces. I will certainly let you know how this all turns out. (later tonight most likely)

It works quite well putting "Grabber MyCoal" non-rechargable handwarmers into a
baby food jar to starve them of oxygen and turn them off. I never knew there were
boil-to-recharge warmers, do you have a brand name or link to a supplier?

I've done it with a heat sealer we had where I work. Sealed them up when I got there and opened again the next morning. I got about 10 uses (10 days) at 30 min each before they start degrading... even then they still work, just not as warm.

it's been a few years since I used them. REI had them at the time. will search.....

https://www.surplusandadventure.com/s...andwarmer.html

something like this...

or here.... https://cgi.ebay.com.my/ws/eBayISAPI....m=380185943642

I just bought a bunch of Hot Hands 2 hand warmers. On amazon you can get 40 sets (80 total) for under $25. Not much need to reuse at that price.

conversely - not much need for a whole case if I can reuse them! -)

re-using a regular hand warmer works. I wrapped it up again and I may be able to use it again later in the week. I'm driving the car for a work assignment tomorrow.

Yes, it works, can stay inactive for a good while if the container is very well sealed. The boil type handwarmers can be reused for longer, but i find they only give 15-20 minutes of usable heat, while working however, they do give out more heat.

Also, it is important to note, if you treat the pouch roughly before opening, ( the original pouch the pack was sold in ) then when you come to use it, you'll find it hard and lumpy, all used up.

Lee Valley Tools sells reusable ones:
Lee Valley

I can't recommend them though: like coldfeet, I find they don't stay warm long enough.... plus, one of the ones I had broke while I was boiling it to recharge it, so I took them back.

They might be okay in a climate a bit warmer than Ottawa's.

I got some reusable ones off ebay for the princely sum of £4 for 4! They work well and fit nicely into the pocket on my gloves.

yep! got two more uses out of it - a ride and a ride home. so I think that makes 6 uses? each use was about an hour or an hour and 20 minutes.

not having baby-food jars handy, I put them in an empty Tylenol container