I really appreciated this book on how air conditioning raised the American standard of living. Before air conditioning, summers were a slow torture of coping with inescapable heat. Theaters, churches and other places of public gathering were insufferable. Attendees were overheated due to the body heat of crowds. Buildings reeked due to body odors of unwashed masses. It was not uncommon for Congressmen to pass out due to heat exhaustion in the middle of a session.

Even U.S. presidents suffered. After enduring a two hour summer ceremony for laying the cornerstone for the Washington Monument, Zachary Taylor in his black suit downed a whole pitcher of ice milk as part of a desperate attempt to cool off. This caused a rupture, and President Taylor died within a few days.

As much of a problem as climate control was for public places, the first major application of air conditioning was for factories. The book tells the story of how Willis Carrier—a Cornell-trained mechanical engineer and future businessman who would soon play a substantial role in bringing air conditioning to a mass market—was tasked with solving a critical problem for the Sackett-Wilhelms Lithographic and Publishing Company, an established color printing company in Brooklyn.

Sackett-Wilhelms, like many industries at the turn of the 20th century, was at the mercy of weather. The quality of their print jobs was greatly impacted by small variations in temperature and humidity. A few degrees too many meant that ink would run, colors would be off, and letters would be smudged. Large print jobs would be ruined by the heat, reams of paper would be discarded and critical publication deadlines would be missed. It was not uncommon for the company to have to halt production for especially hot days.

The critical problem for Sackett-Wilhelms was not temperature per se but the humidity induced by hot days. Could young Carrier help solve this problem? Supposedly, Carrier's critical insight for air conditioning came when he was sitting on a train in Pittsburgh on a foggy night, observing moisture condensing on the window. Perhaps he could suck the moisture out of factory air—and give precise control over humidity—by creating an artificial fog and inducing condensation. This idea became the basis for air conditioning.

After solving the climate control problem at Sackett-Wilhelms, Carrier went on to build similar, fit-for-purpose air conditioning devices for textile manufacturers, soap makers, leather producers, meat packers, brewers, chewing gum manufacturers, and chocolate companies. Can you imagine a chocolate factory trying to operate in 90-degree weather?

Carrier and competing producers of air conditioners went on to design and sell devices to cool businesses open to the public. Movie theaters soon boasted of their new chilled air, offering patrons an opportunity a cool, two hour respite from summer heat in which they could enjoy an entertaining flick. Forward-thinking department chains such as Macy's eagerly embraced air conditioning, seeing it as another mechanism to make their stores more attractive and more pleasant on the nostrils.

By the 1940s, Carrier traveled the country presenting his vision of climate-controlled homes with central air conditioning well before that became common place, and his eponymous company soon made that a reality.

I was particularly amused by Carrier's unapologetic confidence in the safety and efficacy of his products. According to one anecdote, Carrier was enlisted to install an air conditioning system for the Rivoli Theater in New York. After the project began, a building inspector threatened to delay this highly visible endeavor because he was not familiar with the new refrigerant Carrier was using, dielene, and questioned its non-flammability. Confident in the safety of his thoroughly-tested systems, Carrier whipped out a bottle of dielene, poured some into a cup, ignited a match, and dropped it into the liquid before the inspector could object. Having a way with words, the author wrote that although the dielene didn't explode, as Carrier knew it wouldn't, the inspector did, but he soon issued the needed permit.

This is a well-written book by a talented and funny author. My main and only criticism is that the narrative is sprawling at times. Even though I applaud the author for thoroughly illustrating air conditioning's overwhelmingly positive impact on human life, I sometimes felt inundated by example after example after example. I also wish that the book had more Willis Carrier stories, but that is not really a fault.

Cool: How Air Conditioning Changed Everything