It can be sealed to make it waterproof with ease and is light and will fit in a pocket.
I've entered it in the survival competition so please vote if you like it.
1 sweets tin or similar, as long as it's metal and a decent size
some corrugated cardboard
A candle or other source of wax
Electrical tape if you want to seal it.
To make roll the card around the edge of the tin, spiraling around until you reach the middle, then add a few bits of card sticking up for use as 'wicks'. Then light a candle or melt some wax and cover the card in wax, (a thin layer everywhere works best and let it soak in before adding more)
To light, hold a match to the wick until it lights, light other parts as well to get it going quickly if needed.
To put it out just put the lid back on and leave to cool.
the video doesn't show it but the flame does spread out across the whole stove.