Dancers: should (and how do) I let a dancer know if she has an unpleasant odor?

We all run into people who may not have the greatest smell, but with dancers it's particularly important to smell nice for the job.

On a few occasions I've noticed an unpleasant odor (in a few different regions) and I've never been sure how to respond. In some cases it was a one-time for that dancer, in others it was more consistent.

Is this a spinach in your teeth type of thing where you'd much rather know, even if it's embarrassing? Or is it just inappropriate to say anything at all, even if politely?

If the former, do you have any suggestions on how to most tactfully broach the subject? Thanks!