Mountain Biker Succumbs To Hyperthermia

Two horseback riders who were riding the Shantz trail in the park’s Rincon District on the morning of May 30th came upon a man’s body. He’d been riding a mountain bike on area trails and was found lying on part of his bike (mountain bikes are prohibited on these trails). Investigating rangers determined that he was Robert Koch, 42, of Novi, Michigan. Koch’s vehicle was found at a trailhead about two miles southwest from the point where his body was discovered. A ranger had seen it parked at the trailhead the previous afternoon and had run a computer check on it with negative results. The investigation also revealed that one of Koch’s relatives had contacted Tucson PD on the night of May 29th and reported him missing. When found, Koch was wearing a bicycle helmet and there was no sign of obvious significant trauma. The water bottle on his bike was found empty. The high temperature in Tucson on May 29th was 95 degrees and the overnight low temperature was 50 degrees. The temperature when his body was found was 80 degrees. The Pima County medical examiner conducted an autopsy. On June 23rd, the medical examiner advised the park that Koch’s death had probably been caused by “hyperthermia due to exposure to the elements.” Hyperthermia, also called heat stroke or sunstroke, is an acute condition which occurs when the body produces or absorbs more heat than it can dissipate. It is usually caused by excessive exposure to heat.