Prepare ground beef ahead of time.

Before leaving for your camping trip, brown some ground beef (or turkey,game,etc)and put in a freezer bag and freeze. When camping, this acts like a block of ice to help other items to stay cold. When you´re ready to prepare a meal all you have to do is add spagetti sauce, or chili, tacos, sloppy joes, or misc. pasta. It saves you the step of browning your meat in the camp kitchen. In general, any thing that serves a dual purpose is preferred when camping over something that does not. In this case, it´s both a food and an ice substitute.