I know, I am mean, I left you on a cliff hanger there. Wait you shouted! Your going to be camping, a few miles from power possibly, how the world are you going to be able to keep food cold? It is time to get geeky.
I have been thinking for a while now about using the great Lake Superior to cool food. I could just bury my food deep in the sand, but critters might get to it. One idea I have had is simply to have two containers, one with food in it, and a bigger one to keep lake water in to keep it cool. Nice and simple, this will keep the food about lake temperature, of about the 60s during warm summers, and cooler as you go deeper.
Another option involves some kind of device which uses evaporation to cool the food. Using fast evaporating liquids like alcohol, Ben Franklin and a colleague was able to cool a thermometer from 65°, the room temperature, to 7°. It would cost money but I could keep adding alcohol to something to cool it. This is good for maybe something I brought home earlier that day but not for multiple days.
I can do the same thing with water, but this will only cool to the dew point. Something like the container idea plus some fabric as a wick, and water evaporating from fabric would help to keep the water cooler longer.
I plan to test this method and a few others over my summer.
From the guy with his eye on the sky, Travis...the camping lifeguard