Air conditioning
In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. There, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.
Ice cube
American physician and humanitarian John Gorrie built a refrigerator in 1844 with the purpose of producing ice to cool air. His refrigerator produced ice which he hung from the ceiling in a basin to lower the ambient room temperature. During his time, bad air quality was thought to cause disease. Therefore, in order to help prevent and treat sickness, he pushed for the draining of swamps and the cooling of sickrooms.