However, we have personally washed the Ozark brand water bottles and tumblers in the dishwasher at my house without issue for years. The 10 hour mark was where the biggest differences began to show. Nothing had ice left, but surprisingly they all maintained a fairly cool temperature. I would say you could expect ANY of… Continue reading USA Ozark Trail Double-Wall, Vacuum-Sealed Tumbler Stainless Steel 20oz 590ml