Well, there was that time in the Peace Corps back in Ethiopia in the 1960's. I was having a nice lunch with Mary, one of the other volunteers in the village of Emdeber. Among other things she had prepared a garden salad, having previously rinsed the greens in diluted iodine as we'd been instructed by the Peace Corps staff. It did give the salad an odd flavor but we knew that any nasty bacteria would be dead. After lunch I returned to my science classroom and was about half way through the lesson when I felt an irrestible urge to demonstrate the vomit. I hastily told the students to copy everything I had written on the chalkboard and that I would be right back. Which I was after filling a basin in the science lab next door with lunch and perhaps breakfast. By the time I returned to the classroom the students were looking a little concerned but I bravely carried on and then dragged myself home. Mary said she was very sorry, and also very sick, and that she must have made the iodine rinse too strong.