1. Head trauma. Wow! I was completely unaware that patients should avoid this. I figured it might toughen them up, and openly encouraged it. Perhaps I should rethink my opposition to seatbelts and motorcycle helmets, too.
2. Menstruation. I'll let all my lady patients know to stop doing this immediately. I had no idea it was under voluntary control, so I'm glad you told me.
3. Weather changes. I'll tell my patients to immediately move somewhere that has absolutely no weather changes. Like Pluto.*
* Actually, sometimes this doesn't sound like such a bad idea.