A three-layer medical mask with an elastic band must certainly cover not only the mouth, but also the nose, fit snugly to the face. It must be borne in mind that the mask does not protect from the virus itself, but from droplets that are released from a sick person when sneezing or coughing and after three hours becomes unusable. The virus, together with droplets, can enter the body during a conversation, if the interlocutors are closer than one meter from each other. Therefore, it is recommended to wear masks for those who are near a sick person. It is easy to control the change of masks by the staff using colored masks (each color for 3 hours)