In mid-March, Karla Monterroso flew home to Alameda, Calif. after a hiking trip in Utah's Zion National Park. Four days later she began to develop a bad, dry cough. Her lungs felt sticky.
The fevers that persisted for the next nine weeks grew so high — 100.4, 101.2, 101.7, 102.3 — that on the worst night, she was in the shower on all fours, ice cold water running down her back, willing her temperature to go down.
"That night I had written down in a journal, letters to everyone I'm close to, the things I wanted them to know in case I died," she remembers.