solar powered cooler Answered
Using these ideas as a starting point:
"Another variant uses air, water, and a salt solution. Warm air is passed through a sprayed solution of salt water. The spray absorbs humidity from the air. The air is then passed through an evaporative cooler. Humidity is removed from the cooled air with another spray of salt solution. The salt solution is regenerated by heating it under low pressure, causing water to evaporate. The water evaporated from the salt solution is recondensed, and rerouted back to the evaporative cooler."
Directions on how to make an icy ball. URL works occasionally.
Is a non-flammable, non-toxic, and low pressure version possible?