In early August 2015, Chris Lihosit fell ill with an exhausting, dehydrating and pyjama-soaking fever that mysteriously disappeared two days later.
During a check-up, on his 43rd birthday, his doctor named summertime flu the most likely culprit.
Then the same thing happened again, and it settled into a disturbing pattern: midweek chills and an escalating fever that would break on Sunday. By Monday, Chris would feel fine, only to have the sequence repeat itself.
He joked about it with colleagues at T-Mobile, where he works in software development, “Well, I hope it’s not cancer!”
On alternating weekends from May to October, Chris would volunteer as a back country ranger for the US Forest Service — a physically demanding role that involves patrolling Washington’s Cascade Mountain forests and hiking along high-altitude trails with a backpack that can weigh up to 32 kilograms.
But now, even at sea level, he was getting winded just walking his two dogs around the block. What was going on?