If you want to cook in the open, first to find a place where is nearby a river or lake. Then you can boil water, or use water purifiers to purify water. You can carry gravity water purifier or pocket water purifier, which can provide water for family or individual.
In your last post, you mentioned a Diercon water filter straw, I don't know much about it, is it really as useful as Lifestraw?
alicedan and louisgreen possibly from the same stable? The above seems slightly strangely worded for a post.