Face mask use is a social contract. My mask protects you; your mask protects me. But face masks are not perfect and they need to be used in conjunction with other measures to lower risk of infection such as physical distancing and hand washing. There is ample evidence to suggest that widespread use of masks results in significant reductions in the transmission of respiratory viruses. Mask use is grounded in biology and can have a real world and meaningful effect on slowing the spread of infection, protecting your coworkers, and those vulnerable members in your community.