“When I mention to someone that you can boil water with hot stones, they always ask me two questions… Why would you do that? How do you do it? Why would you ever boil water using stones? Why don’t you use the fire to heat it.
Well, in a perfect situation, in a camping situation, that is ideal, and you can just put your pot or container over the fire and wait for it to boil. What if you were in a survival situation, and the only container you had could not be placed over a fire?
Either it will melt, or if heated with a flame, it would leach toxins into the water.
Having the knowledge of accomplishing a mission as critical as boiling water could be a matter of life and death. So we have a container we can’t heat directly, so we use stones to heat the water and get it boiling. We are heating the water, not the container…”