We also made emergency candles with soy wax in an Altoids tin. Two wicks, and fill to just below the hinge holes. I haven't tested whether it gets hot enough to boil water as an emergency stove, but it provides light aplenty, and the lid can reflect heat. Close it and it's snuffed. Then one just waits for the thing to cool and the wax to solidify again, and it's ready to go for next time. Just don't leave it in a hot car, and especially not at any angle other than absolutely flat.
We also made emergency candles with soy wax in an Altoids tin. Two wicks, and fill to just below the hinge holes. I haven't tested whether it gets hot enough to boil water as an emergency stove, but it provides light aplenty, and the lid can reflect heat. Close it and it's snuffed. Then one just waits for the thing to cool and the wax to solidify again, and it's ready to go for next time. Just don't leave it in a hot car, and especially not at any angle other than absolutely flat.