Icy cold air conditioning is very common in many people’s lives, but there was a time when this popular luxury did not exist. People had to think of other ways to keep cool on hot, humid days. It was also too hot in factories and hospitals, theaters and cars. Willis Carrier changed all that. Authors Alison and Stephen Eldridge explore how his love of science and fixing things led to a lifetime of adventure, research, and the discovery of air conditioning.