• Be careful about what you drink in the lab. Mixups do happen.
  • Remember that very hot glass looks exactly the same as room temperature glass.
  • If you don't know, ask (e.g. "What does pyrophoric mean ?" is a very good question). If you cannot ask, get out of the lab.
  • Fear invisible entities that can kill you, like electricity, carbon monoxide and nitrogen.
  • If it is plugged in, it can start working.
  • If it is not plugged in, it can still kill you (big capacitors are installed in the oddest places).

And most importantly: Believe in Murphy's Law.