I have a Polar bottle which I like. I put the empty bottle in the freezer overnight (if available) and fill the frozen bottle with water before I leave - it works well, in the summer.
I also use a Camelback Flashflo, and put a few ice cubes in there, and it holds up rather nicely for about 4 hours - then it gets warm - however, I usually empty it by that time.
Hope this helps.
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