It's been quite cold here and so far I haven't figured out how to keep my water from freezing, even during relatively short rides. Forget regular water bottles - they freeze up in no time. This morning it was 15deg F and I tried a small camelback underneath my outer shell jacket. The water bladder was fine, but the drinking port and about half of the tube froze - and this was the "winterized" neoprene covered one! I had the tube tucked inside my jacket and just left the drinking port right outside my collar. Anyone try those Polar insulated water bottles? Any additives that can be placed in the water - like antifreeze (but non-toxic!)?