According to the CDC: Wear a facemask if you are sick.
- If you are sick: You should wear a facemask when you are around other people (e.g., sharing a room or vehicle) and before you
enter a healthcare provider’s office. If you are not able to wear a facemask (for example, because it causes trouble breathing),
then you should do your best to cover your coughs and sneezes, and people who are caring for you should wear a facemask if they
enter your room. Learn what to do if you are sick.
- If you are NOT sick: You do not need to wear a facemask unless you are caring for someone who is sick
(and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved
for caregivers.
...