The ER air conditioning has been broken for two days, and the trauma bay feels like the inside of a kettle. Somewhere behind you a monitor chirps out of rhythm, a toddler is wailing in the pediatric bay, and the overhead fluorescent light above bed 4 has developed an irritating flicker. You wipe a bead of sweat from your forehead, roll your aching shoulders after twelve hours on your feet, and pick up the next chart.

Bed 4. A young man is curled on his side, one hand pressed to his jaw, the other clutching the thin hospital blanket as though it might anchor him. He barely turns his head as you approach.