Such a great water bottle! Filled this with cold water first thing in the morning, left it in the car while running errands. 3 hours later, I took this to HOT YOGA (which is a 90-min class in a 105-degree room). The water stayed cold and fresh the whole time!!! Totally amazed and very happy with this purchase. The wide mouth makes it easy to clean, and the design is cute. I have the black one but all the other colors look great too.