Its operation is basic and consists of placing a vessel inside a larger one, filling the space between them with wet sand and covering the upper part with a damp cloth. When the water evaporates, it extracts the heat stored inside the vessel with it, thus generating a decrease in the internal temperature. It is a natural, cheap and easy process to make.
In this way, perishable foods that only lasted 3 days (before the decomposition process began) can now last up to 3 weeks. With his invention he won the Rolex Award that distributes $ 75,000 in prize money.
Brilliant ideas are not difficult to execute, here is a clear example of this. The technology has been known for centuries, but has never been applied to this problem.