COVID-19 has mounted a sustained attack on public life, especially indoor life. Many of the largest super-spreader events took place inside—at a church in South Korea, an auditorium in France, a conference in Massachusetts. The danger of the indoors is more than anecdotal. A Hong Kong paper awaiting peer review found that of 7,324 documented cases in China, only one outbreak occurred outside—during a conversation among several men in a small village. The risk of infection indoors is almost 19 times higher than in open-air environments, according to another study from researchers in Japan. Appropriately, just about every public indoor space in America has been shut down or, in the case of essential businesses such as grocers, adapted for social-distancing restrictions. These closures have been economically ruinous, transforming large swaths of urban and suburban life into a morbid line of darkened windows.