In reply to Ecolgan:
What are you expecting people to do with it? And where are you expecting them to use it?
What sort of situations are you looking at where a box of woodchip and coal would be a better solution than the various other ways of staying warm, getting a brew on etc?
(In the last twenty years or so of walking, camping and generalised mucking about in the great outdoors, I've had an open fire a grand total of three times - once in an attempt to smoke the midges out, and twice because we were bored and there was stuff available to be set fire to. :