Another tip for keeping ice in the ice chest while camping: fill your cooler, stock with ice and then pour salt over the ice. I don't know why salt melts ice on your sidewalk and not in your cooler. But I know that years ago, when I filled the salad bar at the local restaurant, I iced around the containers and then salted the ice. It kept the ice from melting and in fact, fused the cubes together. This is what we do, especially when we go to the ocean dock and buy hundreds of pounds of tuna or salmon and need to transport them home several hours.