lol - I can beat that one. At my first gig, before we had anesthesia in house, there was a weekend OR nursing crew available to set up cases. The OLD anesthesia machines could deliver 100% N2O. There was no oxygen fail-safe system, and this might have even been pre-SaO2 monitoring. One of the nurses strapped on a mask and turned on just the N2O. Fortunately the other nurse found her and called a code. A Code Blue in the OR when no surgery was going on caused quite the stir. 🙂