BEIJING — China's National Health Commission has renewed its instructions on wearing medical face masks to help the public defend themselves from the COVID-19 epidemic.

Based on the latest characteristics of the epidemic, the new instructions inform the public to not only wear masks in indoor public spaces but also when in crowded outdoor locations such as parks and squares.

The instructions also listed three lines of professions that ought to wear masks properly at work, including those that deal with imported items and personnel, workers at medical institutions, and service personnel at public venues.

For those who go to hospitals for symptoms including sore throat, cough, and fever, the instructions advise wearing medical masks of higher protection levels.