On a recent trip to The Needles District of Canyonlands National Park backpacking for four days with 3 friends, I filled this cooler with a 12-pack of beer, 6-pack of soda, a bunch of water, along with some oranges and a 7-lb bag of ice. We left the cooler sealed in the back seat of the car, for 4 days, basically in the middle of the desert. Upon our return, having depleted all the water we had carried with us, We we anxious to see how the cooler kept cold. We were absolutely elated to find that the Icemule had retained the Ice, and our victory beverages were about the best, ice-cold relief imaginable after our 4-day, 45 mile journey. THANK YOU ICEMULE!