I thought I told you after our last such discussion but maybe I just did the experiment then forgot to post the results. <img src="/images/graemlins/blush.gif" alt="" /> Anyway I found some rectangular mini pie tin-type tins made for making tiny single serving meatloafs. I folded a couple flat then rolled them super-flat with a rolling pin then unfolded then and used them to boil water over the flame from a propane grill. Worked well... no leaks. I had to fashion a lid for it (small piece of bark works well) but that was it.

I don't remember that. You may have posted it, and I may even have read it, but I don't remember. Thanks.

Are these the ones like you find one person pies in at convenience stores?

Something like it, yes. I also use the rectangular small bread loaf ones. Good size. I just roll up the edges (bit tedious, but worth it) fold it to fit on the bottom of the container, and walk it a few times with a dead blow mallet. I suspect it would be much easier to unfold that than trying to fold a sheet of aluminum foil into a pan when my hands are really cold.

I like those Trianga mess tins too, the ones with the lids. For me they are a bit too big to really be considered "personal". They can go in a rucksack OK, but you can get separated from your rucksack. To be honest, they are too big for me to bring along without a definite intention of using it, so I think of it more as a hiking kit than a survival one. I have found a small tin which was originally a presentation box for a minature bottle of Baileys, which holds about 250ml. I think that's the smallest amount which is worth heating. It is not too big to carry even when I'm not going to have a disaster, but it is still too big for a pocket. (The "You Can Survive" commercial kit, reviewed here, comes in a nice-sized tin too, but it's an awkward shape to carry and the rest of the kit is poor. But it's the kit which first got me into this.)

I'm comming to think there is no good solution. Anything large enough to contain and heat a decent amount of water will be bigger than what I'm willing to carry on my person.