In late March, Scott Aberegg, a critical-care doctor at the University of Utah, was eating lunch in his hospital cafeteria. On his phone, he noticed an e-mail that was circulating among the trainees in his department. It was from the American Thoracic Society, a professional organization of physicians who treat lung disease and critical illness. “As you have undoubtedly heard, there is a coronavirus surge in New York City,” the message read. “The situation is dire . . . and your colleagues need your help.” The e-mail offered same-day credentialling and licensing, as well as free travel, housing, and meals to doctors who volunteered to work in the city’s hospitals. The e-mail was so extraordinary that Aberegg wondered if it could be a scam.