Thank you all for your very informative posts, the information on other forms of water purification is very helpful although not what I asked for. I agree there are many creative and more efficient ways to make water safe to drink than boiling it, what I was more interested in was boiling water for the purpose of making food sources that may contain parasites safe to eat.
Most of northern Ontario hasn't seen civilization since ww2 or the railroad pulled out, well before water bottles were common, hence it could be useful, but cannot be relied upon. Heating water with heated stones was all I could come up with aswell, it is very inefficient and inconvenient but in dire times it could save your life.
I was trying to picture what Native Americans would have done hundreds of years ago... probably barbecue their food
. wooden carved bowls are possible, or birch-bark containers? or an animal skin sack suspended over a fire? Im picturing all the critters you could find in the bottom of a creek, crayfish, mussels and the like. Thanks again for all your posts.