How might a professor approach a student who comes to class and/or office hours wearing perfume or cologne that is distractingly or overwhelmingly powerful?
Certainly, different people have different thresholds for this sort of thing. Lets say that in this case it is unclear the extent to which this is distracting other students in class but it is clear to the teacher that it is strong enough to distract the teacher. Of course, it might be affecting other students as well.