Adventist Youth Honors Answer Book/Camping/Keeping food cool
One way to keep food cool without ice while on a camping trip is to place the food in a mesh bag and secure it in a stream or brook. Another way is to put the food in a bag, cover it with several layers of burlap, wet the burlap, and suspend it from a tree branch. As the water evaporates from the burlap, it will cool the food. You have to re-wet the bag occasionally.