As more than 5 million World Cup fans visit the United States, many are learning something Americans have known for generations: air conditioning is a necessity. In much of the country, it is what makes daily life, work, commerce, and even outdoor events possible during the summer.

Some visitors who once mocked America’s dependence on air conditioning are quickly changing their tune after experiencing the heat and humidity of places such as Texas, Florida, and Georgia. The world is discovering the value of modern cooling just as global demand for it is exploding.