Face masks have become a common object during the pandemic. They are seen in supermarkets, restaurants, and public transport. Although using them before the outbreak of the coronavirus meant receiving some strange looks, now they are the norm, especially in urban centers. This change in habits has been reflected in a world survey carried out by the University of Maryland and Carnegie Mellon University in alliance with Facebook, which details that almost nine out of ten Mexicans have adopted the frequent use of masks. The figure reported in Mexico is the third-largest in the entire continent —only behind . . .