Air-conditioning detractors like to point out that people managed to survive for millennia without it. From this point of view, sweltering weather is a natural reality that humans shouldn’t meddle with, an attitude that bears some worrisome resemblances to 19th-century Western notions about how people residing in tropical climates were inherently lazy and shiftless.
The same, of course, is true for vaccines, antibiotics, and sewer systems. People survived without them, apart from the ones who didn’t. And even today, a lot of people don’t survive extreme heat events. At least 600 people die each year in the United States from extreme heat events: That’s more deaths than from storms, floods, and lightning combined, according to climate researcher Kelly Sanders. That figure is probably a major underestimate, because the U.S. medical system still struggles to attribute deaths to heat or track how many such deaths take place. Heat injuries and deaths also cost money. A 2012 case study covering data from 11 U.S. states in found that the costs from heat-related injuries and deaths totaled over $10 billion. These costs are expected to rise as the country heats up.
Young people, the elderly, people with disabilities, and those who must labor outside face the most risk from heat, although everyone is vulnerable. Dying from heat stroke is not a pleasant way to go: Your brain swells, your organs begin to shut down, and you may begin to convulse—or slip into a coma. And you can die from heat with shocking speed. People can go from feeling vaguely unwell to dead within 90 minutes.
A study published in 2016 found that Americans’ risk of death on a very hot day has fallen by 80 percent since the 1939-1959 period, with most of the gain coming after 1960 —an improvement researchers attributed almost entirely to the spread of home air conditioning. That’s a number that would translate into 20,000 more deaths each year in the US if we maintained midcentury rates of heat-related deaths today. Researchers also found that this protective effect was particularly strong among vulnerable populations, including Black Americans and those ages 65 and up. This pattern holds true globally. A major 2021 research report in the Lancet estimated that, globally, access to air conditioning averted 195,000 heat-related deaths among people ages 65 and older in 2019.
In simplest terms, then, millions of people are alive today who would be dead if not for air conditioning.
Many people assume that air conditioning is worse for the environment than heating is. After all, why do we hear about it so much more? The truth is that heating a home uses considerably more energy than cooling one does. A 2020 study found that homes located in the coldest parts of the United States used considerably more energy and largely emitted more greenhouse gases than those in the warmest parts of the country did. A 2013 study concluded that living in colder climates in the United States demands more overall energy than living in warmer climates does: Climate control in Minneapolis uses about three and a half times more energy than it does in Miami.
In this light, it’s curious we spend more time criticizing people in dangerously hot climates for running the air conditioner than we do finger-wagging at people who run an oil-burning furnace during a Northern winter.
