The technique is thousands of years old. The Australian version is the Coolgardie safe:
It’s a wire mesh cage with damp cloth on its outside. As long as you keep the cloth damp, and the air is not 100% humid, the contents keep as cool as in an electric fridge.
Other versions use the same principle with unglazed clay pots, kept damp. Ilana Strauss describes a version that will work for a considerable time without needing attention: a large pot holds a smaller pot, with sand in between. You wet the sand, and fill the inner pot with food.
Given that 15% of electricity use is for refrigeration in the typical home, this is a good trick to keep in mind. And when the grid fails, it still keeps working.
Bobbing Around 
Awesome! It reminds me of ice boxes my grandmother had.
Never Give Up
Joan
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I remember those, too, but they do need ice. Evaporative cooling is even better, especially in hot places.
🙂
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Yes, evaporative cooling is indeed better!
Never Give Up
Joan
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