Heavy Duty Aluminum Foil 3 sq. ft. (0.9 sq. m), make container to boil water, reflect fire heat and much more Heavy Duty Aluminum Foil3 sq. ft. (0.91 m) Heavy Duty Aluminum Foil: Sturdier than standard lightweight foil, ours has enough substance that with care it can be used to form a container to boil water for purification purposes. It can also be used as a reflector behind a fire, to protect dry wood under a fire built on snow (if there’s no ready supply of green wood) as well as for many other purposes.