What do I do if one of my teachers has horrible body odor and makes the entire classroom smell terrible? Should I let the teacher know anonymously or just ignore the issue?
I'd probably sit back until it's unbearable and then jump out the window. (But in all seriousness, no idea. Tipping your teacher anonymously sounds like it could go either way - Either they take it offensively or neutrally - guess it also depends on how you write the note)
Actually, do it, why not. If it's really unbearable, do it for the sake of the class and probably your sanity. I mean there are worse things that could offend a teacher anyway. This probably isn't one of them, unless you know they'll be touchy about it.