I was luckily able to easily locate the breaker panel when I got home today, and also easily found which circuit I was looking for, because it was the only one switched to off. So I flipped it back, and all is well!
Well, except perhaps my vanity, because I didn't see a mirror until break time, an hour and a half into class, and it was quite obvious that I had not looked in a mirror this morning. Also that I needed to have washed my hair. =sigh= Oh well, I don't think anyone had the impression that I was cool anyway.