[Andrew WCY]

Whenever I feel urgent and can't hold it any longer in a classroom, I'd always ask a teacher for permission to go. In a lecture theater, however, I'd probably just get up and go. Professors probably wouldn't care too much about that.

If I were helping someone else out in an occupation, the first thing I'd think of is to find someone else qualified to help them and head towards a washroom. I'm not quite sure how to deal with the other case when there's no one else to temporarily take my position though.