I suspected this would not sustain me through a 3-hour class (which was scheduled to include a showing of a documentary), given that I have seriously fallen asleep in class 2 nights in a row. So I went to Dunkin's and got a small iced hazelnut coffee with milk and sugar. (Mind, I have never had more than a couple of sips of coffee because I don't like the taste of it and prefer the GET SOME SLEEP method of dealing with tiredness versus caffeinating.) I drank the whole thing over the course of the hour I had before class (all the while reading for class and mostly not spacing off). I was intermittently bored during class, and I was aware throughout that ideally I would like to be getting a full night's sleep, but I was awake the whole time. And sometimes I'd start thinking about other stuff and zoning out on what the professor was saying, but I'd actually return my attention to the professor fairly soon -- rather than falling asleep rather soon, as is my usual m.o.
Drugs, they're like magic.
And now I am going to bed. We shall see see whether I successfully fall asleep.