Measles requires airborne precautions because its viral particles are smaller and can remain suspended in the air for up to two hours after an infected person leaves the area, unlike typical droplet-spread diseases. Droplet precautions (e.g., masks, 3-6 feet distance) suffice for larger particles that fall quickly, like influenza. Measles’ ability to linger and spread through ventilation systems necessitates negative-pressure rooms and N95 respirators for healthcare settings. This distinction stems from its high infectivity—up to 90% of susceptible contacts may get infected.