I was looking around a bit today for some possible options if one were to be in a spot like I was without the tremendous aid of having other around. That's when I found
these.
http://ecx.images-amazon.com/images/...A300_SH20_.jpg
If I were to find myself in a situation that I could not light a stove and needed a hot beverage to recover, this might be a good option. I may have to pick up a case of these and leave one in an easy to access part of my pack.
I may have to play around with one to see if it will heat the Cocoa (soups are also available) and perhaps have enough heat left to warm some water after drinking the original contents. This might be one of those heavy and bulky items that still earn a place in your pack.