OrionWorks wrote:
Jed sez:
...
I mean hand warmers. "Disposable chemical pocket warmers." Little plastic
bags full of chemicals, mostly iron filings, I think. You smoosh or bend
the bag to mix the chemicals, and it gets hot for several hours. I guess it
puts out a couple of watts. I am trying to think of what they are called .
. . Ah, "kairo." See:
http://www.scienceiq.com/ShowFact.cfm?ID=212
http://www.sportstek.net/hotteeze.htm
Apparently you have to admit air into the bag. It would be interesting to
see what would happen if a whole box of these things was damaged.
I have not seen these in the U.S.
They do exist in the U.S.
I used them on a Wisconsin skiing outing back in the 70-80s. They worked quite
well keeping my hands warm on the chair lift.
Regards,
Steven Vincent Johnson
www.OrionWorks.com
The ones I have are an American make. They use a exothermic salt
crystallization reaction. The jell goes hard as it crystallizes and
generates heat. The thing goes soft again if you boil it in water. I've
had them for about 10 years. There very nice in a sleeping bag on a cold
army exercise. I have a solar stove design using these things heat them
by day with the sun and use them at night to cook diner.
