It’s 3:00 a.m. in the emergency department, and your feet are throbbing. The air smells faintly of bleach and stale sweat. You’ve just managed to steal a moment in the cramped on-call room, hoping to inhale a cold sandwich, when you hear the automatic doors open, followed by general commotion that can only mean one thing: an acutely ill patient. You sigh, drop the sandwich, and head back out to the chaos of the floor.