I threw up 17 times on a Southwest flight last year. Longest 5hr flight of my life. Somehow made it to one of their *2* lavs each time. I knew that boarding the flight while sweating, despite it being 65 degrees on the terminal, was a bad sign.

I have also witnessed several medical incidents which all ended in the passenger vomiting all over the medical staff that answeed a page, then immediately feeling better. Both times the doctors had no change of clothes in their carry on. Sad the airlines can't have a pair of scubs on hands for emergency clothig changes.