Shannon York says he remembers thinking there was a spider in his hair as he ran his hand through his scalp at summer camp years ago.
He didn't give it much thought until later that day, when he got a fever.
His mom put him in a bathtub filled with ice, but the fever persisted and he ended up in the emergency room.
The spider turned out to be a tick, the kind that carries Rocky Mountain Spotted Fever, and York spent a week in the hospital, fighting an infection that can be life-threatening if untreated.
York, now the marketing and communications manager for the Siskin Children's Institute, said he has been much more careful ever since when he goes outdoors, wearing high socks and paying attention when he walks through high grass.