This reminds me the other night we were watching those two guys who try to survive in different locations. One pulled out a condom and filled it with about 2 ltrs. of water and hung it by a fire to boil. It will boil the water but not melt. Amazing! However, my 11 yr old DGD starts with the questions. How to gently explain..............not me, I called her Dad and turned that conversation over to him.