Yeah! Where is that guy?? Sheesh.

Oh, wait, that's me.

Seriously though, I haven't had a lot of experience with flameless ration heaters. The only ones I've used are the US military ones that come with MRE's. They work, and it's an extremely clever idea. I was a little turned off by the amount of trash left over. The expense and weight have already been mentioned as has the lack of flexibility -- they will heat a packet of food, but they're not much for boiling water for treatment (or just for a cuppa).

My overall impression was that they weren't very practical, but in places where stoves are forbidden, I can see their clear utility.

For something like a GHB (or the like) that you'd put in a car trunk, hmm. Not sure they'd be stable. And (potentially) hydrogen gas in an enclosed space right near a heat source (the exhaust system). Dunno about that. For trunk kits, my money is on ESBIT type fuels.

For travel, I'm not sure if flameless heater kits are acceptable on airlines. I wouldn't allow them if it were up to me, but there may be a loophole in the regs here. Still, would you really want to bring something on an airplane that could emit a highly flammable gas (hydrogen)? That's not sounding like a good idea.

How about sea kayaking? Or river rafting? That might be an application where they'd be good. They can be sealed into a dry bag fairly compactly. Might give you a nice hot meal. I think an ESBIT stove might do just as well, but I could see flameless ration heaters as having utility here.

Just my thoughts. I'll be interested in hearing about how they work in practice. I think they'd look really good next to photos of a classic Primus 71.

HJ