COVID-19 is a nasty illness, caused by a virus named after a beer. The virus pretty much shut down the world in 2020 and 2021.
- wikipedia:N95 respirator - a face mask meeting the N95 standard of the wikipedia:United States National Institute for Occupational Safety and Health (NIOSH)
- wikipedia:KN95 - this is the Chinese standard similar to the U.S. N95 standard.
- wikipedia:KF94 - this is the South Korean standard similar to the U.S. N95 standard.
See wikipedia:FFP standards for more information about global standards.
There are different places selling "N95", "KN95" and "KF94" masks. In short, they all usually work better than pulling your shirt up over your nose.