A century ago, the first way to fight a new virus would have been opening the windows.

Miasma theory—discredited, of course, by the rise of germ theory—held that disease came from “bad air” emanating from decomposing matter and filth. This idea peaked in the 19th century, when doctors, architects, and one particularly influential nurse, Florence Nightingale, became fixated on ventilation’s importance for health. It manifested in the physical layout of buildings: windows, many of them, but also towers erected for the sole purpose of ventilation and elaborate ductwork to move contaminated air outdoors. Historic buildings still bear the vestigial mark of these public-health strategies, long after the scientific thinking has moved on.

Source: We’re Just Rediscovering a 19th-Century Pandemic Strategy