I've always been one of those skeptical people who doesn't believe when "claims" are made about insulated bottles. This bottle ACTUALLY keeps ice at least all day, even in the hot sun. It'll probably keep ice even longer, I just always drink it all before the day is up. The quality of the bottle is also the best I've ever seen...especially around the mouth of the bottle. Easily the best bottle I've ever used. I would definitely recommend a Hydro Flask bottle to anyone.