Interesting idea! Hiking I fill my hydration bladder with ice cubes then add water and I slip the whole thing in an insulated bag, but I never thought of using

Interesting idea! Hiking I fill my hydration bladder with ice cubes then add water and I slip the whole thing in an insulated bag, but I never thought of using an actual ice brick for cooling. (And in most situations I don't think I would, anyway--too much extra weight. The ice in my pack becomes drinking water later.)