dry ice is a clutch item to have during bonnaroo because it'll keep you're coolers cold for the entire 4 day festival. if kept in direct contact with your drinks, dry ice will freeze them. try using it on the bottom of the cooler and placing regular ice on top. the dry ice will keep your ice from melting, and your ice will keep your beer cold. perfect! it might be easiest to search on a smart phone when in the area.