Ive been looking around online and found out about these arctic military canteens, and was wondering if anyone has any experience with them? im really not after one to stay warm while freezing outside, but wondering if it keeps the water cold during a hot day? everywhere ive looked they say there good for winter and have kept them from freezing, so it should do the same for heat no? unless you keep it in the sun, grant it you cant cook in it but they have a large cup, any ideas or thoughts on them? thanks JR