In the current pandemic, the wearing of masks or improvised facial coverings is mandated in most public locations in an effort to reduce the spread of the respiratory coronavirus 2019 (COVID-19). Medical-grade masks such as the N95 are known to provide the best protection against breath-borne pathogens. With such masks in short supply, the general public has resorted to wearing homemade masks or improvised masks made from scarves or bandanas. “Cloth face coverings are intended to keep the wearer from spreading respiratory secretions when talking, sneezing or coughing,” says Steven Gordon, MD, Chairman of Cleveland Clinic’s Department of Infectious Disease. “Cloth face coverings are not personal protective equipment, and it is uncertain whether they protect the wearer.” Nevertheless, cloth face coverings can be effective and do have a place. We asked Dr. Gordon and pulmonologist Raed Dweik, MD, Chairman of Cleveland Clinic’s Respiratory Institute to explain the scientific justification for wearing simple masks that Dr. Dweik and three colleagues recently published in the Journal of Breath Research.