Yes LE but we know you are super-human.
I unfortunately am not.
The students hang in as well!!
If they need to go to the bathroom, they slip out unobtrusively. They don't seem to drink during the class so much. My lemon tea is filled to the brim at the beginning of each class and works its way down by the end. And because these courses aren't totally lecture courses as such but a combination of lecture and discussion, they tend to stay involved.