There is perhaps nothing more entertaining to students than a professor teaching under the influence of lots of cold medication.
Yes, folks, I decided (by this I mean that my germy students decided..) to welcome February in with one heck of a flu case. Buckets of hand sanitizer have been evaporated. It's possible that I'm now addicted to pseudoephedrine. My nose is puffy, red, and shredded.
My lectures were...interesting...this past week. Students actually didn't catch on that I was sick until Thursday. One student commented that they all were placing bets on how much coffee I had consumed pre-lecture. (aw, how sweet).
I have certainly lectured in a worse state. There was the time I gave a lecture, only to realize later that I had a fever of 103 F. The week that I guest lectured during an allergic reaction (one that made it impossible for me to keep any food or liquid down) was particularly memorable for me.
Obviously, none of us want to infect our students. But sometimes, you just have to suck it up and get through the 60 minutes.
What's the worst state that you've been in during lecture?