Awkward text messages from exes, career uncertainties, generalized aches and pains: They all disintegrate beneath the hugeness that is someone else’s life in your hands. The guy’s heart is failing; fluid backs up in those feebly pumping chambers, erupts into his lungs, climbs higher and higher, and now all you hear is the raspy clatter every time he breathes. Is his blood pressure too high or too low? You wrap the cuff on him as your partner finds an IV. The monitor goes on. A thousand possibilities open up before you: He might start getting better, he might code right there, the ambulance might stall, the medicine might not work, the elevator could never come. You cast off the ones you can’t do anything about, see about another IV because the one your partner got already blew. You’re sweating when you step back and realize nothing you’ve done has helped, and then everything becomes even simpler, because all you can do is take him to the hospital as fast as you can move without totaling the rig.