I’ve used this water bottle twice now and have been pleased both times.1st time I poured some sweet tea in it from my fridge (no ice) and was stuck in a hot and muggy high school gym for about 10 hours. It stayed satisfyingly cold for about 9 hours.2nd time was last night. I put it through a test, if you will. I stuck 8 ice cubes in it (didn’t fill it with ice) then filled the rest with cold tap water around 8pm. About 1130pm I checked and there was still ice in there. Probably about 1/2 the size of when I started. Checked it this morning at 6ish and no ice but was very chilled drinking it. Checked again about 10 and was a little warmer but still satisfying. It’s now 2 pm and not at room temperature.I have it in an east facing room and the thermometer in here says 82.9 f.I like the dark bottle color and contrasting light blue. The kid makes it easy to hook it to a backpack or belt loop with an s hook.Overall I’m very pleased. Seems if you want it to stay colder longer, put a lot of ice in it. (Easy to do with a semi wide mouth)*note* I bought this on my own dime. Review by kathy hysong on April 18, 2016