Powerless cooling

"Apocalypse" frequently means no power. But so does "rural Africa." A very inventive Nigerian man named Mohammad Bah Abba developed an incredibly easy evaporative cooling system called a Zeer. Take an unglazed terracotta pot, and fill the bottom with sand. Put a smaller pot inside it. Fill the gap with sand. Add water to the sand. The water soaks into the pots and slowly evaporates, which causes cooling. Apparently it works quite well.

Terracotta is a great PA material because A), it's everywhere, B) it might actually survive the ravages of time and weather, assuming it doesn't get smashed, and C) you might actually be able to make it yourself. Hit up any garden or home store and you'll find plenty of big planters. For that matter, check your neighbor's houses. They may have a few as well, already in use.

More on Bah Abba and the pot-in-pot refrigerator at Wikipedia.