Few days for the school I teach in to go on mid-term holidays, the students wrote exams. We call it Mid Term Exams, and we had to invigilate most of the papers they wrote.
Invigilation is a very tough work. You have to be attentive, and walk through the lanes. It is advisable to be in ballet flats.
You all know, I love high heels. I conquer the world in high heels, and chill in wedges. But if you know, you would be walking through a bunch of students, sitting at their desks, fighting for their retentive memory battle, you need to wear flats.
Trust me, I have a testimony.