Being Sick

Today, I learned that when I see, hear, and smell someone upchucking, it makes me want to be sick too. I wonder why... association of sounds and smells with physical action? Perhaps something like Pavlov's dogs? It took quite a lot of effort to keep it down and remain professional, but I still couldn't bring myself to 'analyse' the results afterwards.. apparently it was orange. I'll take my supervisor's word on it...