Why air conditioning is to blame for Transformers 3

"In 1902, a 25-year-old engineer from New York named Willis Carrier invented the first modern air-conditioning system. The mechanical unit, which sent air through water-cooled coils, was not aimed at human comfort, however; it was designed to control humidity in the printing plant where he worked. In 1922, he followed up with the invention of the centrifugal chiller, which added a central compressor to reduce the unit's size. It was introduced to the public on Memorial Day weekend, 1925, when it debuted at the Rivoli Theater in Times Square. For years afterward, people piled into air-conditioned movie theaters on hot summer days, giving rise to the summer blockbuster." — From Will Oremus' recent Slate.com article on the history of the air conditioner.