Many of us have to attend clinics/outpatients for anything from a blood test to a face-to-face with your consultant. You will be expected to wear a mask unless there are very exceptional circumstances. However, this is expected to be a proper mask and as time has passed scarves, bandanas and some people's (home made) interpretation that could never provide an effective seal will have to change them for something suitable.
As an aside the masks do not deplete your oxygen levels!