Old Kingdom of Egypt
There is evidence that evaporative cooling may have been used in North Africa as early as the Old Kingdom of Egypt, circa 2500BC. Frescoes show slaves fanning water jars, which would increase air flow around porous jars to aid evaporation and cooling the contents. These jars exist even today and are called "zeer", hence the name of the pot cooler. Despite being developed in Northern Africa, the technology appeared to have been forgotten since the advent of modern electrical refrigerators.