I was just looking around in my local outdoor-shop. Trere I saw a bag filled with blue gel and a little metal plate inside. The brand was Vaude (German). I asked it to the sailsman and he told me it was a heat pack.
If you snap the metal plate, the gel would become solid and warm up to a temperature of 55 Celcius. After about an hour, it gets cold , but if you boil it in water, it becomes liquid again.
It's reusable for about 100 times.
I got one for free from him. Regular costumer you know...
Has anyone of you used these before? Are they a good replacement for chemical heat packs?
Let me know.
<img src="/images/graemlins/confused.gif" alt="" />

I have had one for about 10 years. In the USA they call it a re-heater. Mine is the 8" X 12" version. I like it very much. The gel has become much more crystalized with age, but it does not seem to affect the heat output. I like mine better than the chemical packs (it is much larger) but it is heavier as well. I'm glad to see they still make them. I may buy another one.

they become warmer than the chemical ones, but also last considerable less longer. Also i have a issue with the durability. I dropped one in hardened state and the plastic bursted open. Since it was in solid form it didn't leak, i tossed it.

You know there are also heaters that uses lightergas to warm up using a "catalysator" thingy.

I bought mine from Globetrotter.de .
I have used them a few times .
I can't really compare with disposable ones : the only disposable ones I have used so far didn't work at all !!! <img src="/images/graemlins/confused.gif" alt="" />

So these are much better !!
And it's easy to see if they have been used or not !!

They are pretty neat and work well. Just don't carry them in your pack. They have a tendency to activate occasionally from any shock, like dropping your pack.

My wife is even selling them. She (with my help) is setting up a "romance and relationship" web store (woman stuff). This is one item in her "massage" section.

What could possibly be more manly than a bright red heart-shaped heating pad in your BOB? <img src="/images/graemlins/blush.gif" alt="" />

Any takers? <img src="/images/graemlins/grin.gif" alt="" />

I'd hazzard a quess that there's a slight difference between the reheater packs you're talking about and the reusable heat pads sold in outdoor store onlyu becasue I noticed from your link they sell a face mask version. I know from experience that the reusable heat pack I have would be intolerable on the face as it gets to hot. I put mine in a sock if I need it becasue it's too hot for the hands.

I carry a couple to augment the chem heaters. Like others have mentioned, they heat hot and fast, and cool down fast. So they are real good at getting a jump start for warmth, perhaps even in an emergency tucked in the armpit, but not for providing long term warmth. I've used mine a couple of times to provide quick warmth to a scout who's sleeping bag isn't keeping him warm enough. I also provide an extra blanket or summer bag (we keep a few cheap ones in the troop trailer) for a "permanent" solution. But the quick heat thwarts hyperthermia when combined with a warmer sleep system.

Since they cool off after 15 minutes or so, they aren't much use for all day or night heat. Oh, they are also VERY cool to watch as they crystalize and make a good intro to the chemistry topics of endothermic and exothermic reactions.

"I've used mine a couple of times to provide quick warmth to a scout who's sleeping bag isn't keeping him warm enough."

In my tent-camping days I used it for the same thing. I'd wake up freezing at 3:00 AM, push the button, and I'd be good to go until it was time to get up <img src="/images/graemlins/smile.gif" alt="" />. Mine lasts a lot longer than 15 minutes though. I'd say I get 2 hrs of useful heat out of it per use. And it is reliable. About half the chemical ones I've used over the years have turned out to be duds.

So, they are not all that great for all-night use...

Which leads me to...

hand-warmers powered by Zippo lighter fuel...

I know that they used to sell these things years ago. You can still get them used off of eBay, but not brand-new any more. Why? Did some people burst into flames using those things? If they are safe, I was considering grabbing one or two.

The still make them. Cabela's sells them here

They work great. I use one duck hunting.

They are safe, but you obviously need some ventilation since it is "burning".