I would shape it into a bowl without any seams. Then place it near the coals but not directly on them. Remember, aluminum foil will burn on hot coals.<br><br>I've never boild water in aluminum foil, but I have with a paper cup. The water in the cup keeps the temp of the paper below combustion. But if you put it directly on the coals, the part above the waterline will burn off, making it very hard to retrieve when done!<br><br>Have fum.