OK, so you crack the nickel in one of these in the late afternoon when the sun goes down and your hands are starting to go numb:

1. The obvious - as a hand warmer.

2. Put under a canister stove base to keep the canister warm in cold conditions as you cook dinner.

3. At night, place it in your fleece underwear, right next to the femoral artery. It's bliss, I'm telling you. Or, in your boot liners/socks to keep the feet warm at night.

Crack another one in the AM and reverse the process.

Good ideas. Has your femorral artery responded better to one brand over another? Too many of the hand warmers I've tried were inconsistent, some turning cold in an hour. Could be old stock.

The brand I hear most praise for is the Grabber MyCoal brand. I bought a few last winter but have not used them yet.

New question. Okay, so why not use the toe warmers rather than the hand warmer? The toe warmer has adhesive that could be used to keep the warmer in position. Or you could leave the adhesive on and still use it. The size may be a bit smaller.

While I have not used thes yet, I hear that Grabber (accelerated rust-based technology)footbeds/innersoles do not work very well.
I can only surmise that since oxygen is needed to start the warming chemical reaction, that the lack of oxygen inside the boot impedes them from working as well as would when exposed to more air. Any comments from the field?

Given your description of "bliss" are you sure you didn't slip your warmer a little closer to the pudendal artery than the femoral?? It just might work.....

MyCoal Body Warmer w/ adhesive is bigger that the hand warmer & lasts in excess of the advertised 12 hours. I don't go anywhere with out them & use it at night just above my L. ankle to avoid muscle spasams which always occur without the warmer. I'm cert. in backcountry first aid & would use them for hypothermia if necessary. They have always worked for me-no duds, even after a year. I'v had very little success warming a butane cannister below 30--sticking the cannister in my jacket for 10 minutes does work.

I have used these for years. I have also gotten a BAD burn from using foot warmers in areas OTHER than a shoe or boot. They are made to work with less air and so when used outside a boot they heat up enough to blister you (me) if you are too cold to worry about that or asleep! I have pretty good success with the foot/toe warmers but my feet sweat a lot normally so I need to keep scrunching them when sitting for long periods. The main reason I posted though is hand/body warmers on the body and toe/foot warmers ONLY in boots !!!! These things are great and I feel ok with field stripping them down when they are dead and leaving the elements and packing out the paper cover. It is a black mess doing this though so have soap and water for your hands.

Thats a great thing to know. It seems obvious but some people might try putting them in other places. I have never used hand/foot warmers before but I plan on using them this winter. Hope they work out OK and I will make sure to keep them in my boots :)

Re: Point #3 in the initial post. The warmers work incredibly well when used this way. Some people swear by sleeping with a bottle of hot water between their legs, but the chemical warmers are better, in my opinion. They pretty much stay in place. I used one a few nights ago. It was a 'Stay Warm' brand, 4x5 inches, advertised as good for 24 hours. I was shivering, standing in the snow on top of a mountain, watching the moon rise and then the eclipse. Within minutes I felt warmed from inside out. Hard to explain, but the effect was dramatic.
I used it for about 15 hours (overnight in the tent) and left it on the counter when I got home, still very warm to the touch.

I've heard of re-wrapping these things (taking the oxygen away) and re-using them if they're still warm, but I wouldn't want to depend on a used one.

Edited by Trudy on 02/24/2008 10:09:35 MST.

Two weeks ago, I tried the following as suggested by a cashier at an Army surplus store: place the warmers on the dorsa of my feet (on top), above the liner socks (I had silk) and underneath the heavier socks (wool in this case). Blood flow to a foot is dorsum, toes, then plantar surface so the blood carries heat to the rest of the foot. It works.

I tried these for the first time last weekend. Ski trip; ambient temps -5C. First 1/2 of the day my toes were painfully cold. Stuck hand size warmers under my toes and put them back in the boots. Second 1/2 of the day; same conditions, my feet were just cool, not cold. Im sold. The person who gave these to me also explained there is wide variability in their duration. Most fall very short of advertised duration.

Supposidly these have extreme insulating properties, and have been used on Everest and in foot races across Death Valley. Anyone?

The aerogel material provides about 3 times the insulation for a given thickness as Evazote foam. However, it is more than 3 times as dense, so it is actually less warm per ounce than conventional foam. But, in a footbed application where low volume is very important, it's an excellent material.

Toasty Feet has changed the design of their aerogel footbeds. The old ones had a thin area near the toes and around the edge that was a bit uncomfortable, and limited durability. The new version is full thickness to all the edges and (I expect) will have better durability.

Cheers,

-Mike

I was under the impression that aerogel was the worlds least dense solid, in fact only 3 times heavier than air.

Laboratory grade pure Aerogel indeed has the lowest density of any known solid.

But...

To manufacture a product that is cost effective and durable enough for commercial applications, Aspen Aerogel increases the density dramatically over what is theoretically possible. Then, they infuse it into a felt-like substrate which increases the density further. (In a typical Aspen Aerogel material 85% of the weight is aerogel; 15% is substrate.)

Cheers,

-Mike

Edited by MikeMartin on 06/03/2008 15:45:14 MDT.

Gotta say these are great...

I try not to rely on them too much and just accept the temps so that i am still quite dexterous when needed

and in fact i can confirm they can be opened used and put in a vaccum bag (what i did) then reused two days later to the same warmth.

Thunder H.

I've used these type of hand and body warmers to help areas of injury, namely spine and hip, with excellent results, for the last 20 years.

Just come across a body warmer sized pad, which is self adhesive, lasts 12 hours and is sold 3 to a box for £1 ($1:60).

We have Pound shops in the UK, and these heat pads are in the medical supplies section, along with hand and foot warmers.

There's also heat pads which come with an elbow, knee or wrist elasticated tube bandage that has pockets for the (hand warmer sized) heat pads.

The brand name is 'Master Plast Heat Relief' and they work as well as the Mycoal brand, at way less cost!

I guess the Dollar Stores would be the US version of our Pound shops.

here, We would call them 99¢ stores.

they can be an endless resource for all kinds of little knick knacks.

I like to take a few on longer hikes, when I am pushing the edge on my sleep system; for that night that just insists on getting colder than you expected. I also have a dozen or so in my car emergency bag, in case I have to spend a night or two in the car.