The healing properties of fresh air have been appreciated since ancient times,1 when Pliny the Elder (A.D. 23–79) recommended that people with tuberculosis breathe in the air of evergreen forests. We now know that air happens to be high in ozone, a known germicidal agent.2
In more recent history, outdoor air was considered part of the standard treatment for tuberculosis and other infectious diseases.3 Ironically, the “high-tech” hospitals of modern day, with their enclosed, indoor close quarters, may be facilitating the spread of disease far more so than open-air hospitals of yesteryear.
