If physical distancing is difficult to maintain — e.g. on public transport — covering your face with a mask can provide some extra protection. You will still need to maintain all the regular protection measures.
The main value of wearing a mask is to protect other people. If the person wearing the mask is unknowingly infected, wearing a mask will reduce the chance of them passing the virus on to others.
For people at increased risk of severe COVID-19 themselves because of older age or chronic illness, physical distancing is most important. If you cannot maintain physical distance, wearing a mask is an important protective measure.
For people who choose to wear a mask it is important to wear it properly:
• wash or sanitise your hands before putting it on or taking it off;
• make sure the mask covers your nose and mouth and fits snugly under your chin, over the bridge of your nose and against the sides of your face;
• do not touch the front of your mask while wearing or removing it;
• do not allow the mask to hang around your neck or under your nose;
• do not reuse single use masks; wash and dry reusable masks after use and store in a clean dry place.
Source: Australian Government — Department of Health