If you haven't seen these Zeer Pot's, you should check them out. Especially if you are in a really hot climate. I've known about these for awhile now, but I've not had the need to use them as I am in a colder climate.
Basically it consists of one earthenware pot set inside another, with a layer of wet sand in between. As the moisture evaporates, it cools the inner pot, keeping produce fresh for up to three weeks.
Here is a link to a site that explains them a little more.
I think that this is just good knowledge to have in your head in case you ever find yourself in a situation where one of these would come in handy. And I'd bet that there are certain areas of Idaho where these would work really well.