Negative room pressure is an isolation technique used in hospitals and medical centers to prevent cross-contamination from room to room. It includes a ventilation that generates “negative pressure” (pressure lower than of the surroundings) to allow air to flow into the isolation room but not escape from the room, as air will naturally flow from areas with higher pressure to areas with lower pressure, thereby preventing contaminated air from escaping the room. This technique is used to isolate patients with airborne contagious diseases such as: tuberculosis, measles, chickenpox, Severe Acute Respiratory Syndrome (SARS-CoV), Middle East Respiratory Syndrome (MERS-CoV), influenza (flu), and Coronavirus disease 2019 (COVID-19).