Review Question - QID 219812

A 22-year-old soldier collapses during a weighted 10-mile March with an ambient temperature that day of 28.8°C (84°F). This was the seventh day of field exercise, during which the soldiers were required to carry their drinking water each day. Prior to collapsing, members of his platoon reported that he was behaving erratically, and he is currently unable to clearly answer simple questions. On exam, he is found to have sweat-soaked and pale skin. A rectal temperature probe is unavailable, but his temporal temperature is measured at 39.4°C (103°F). Vitals include a systolic blood pressure of 100 and an elevated respiratory rate. The battalion surgeon decides to delay transfer to the hospital and immediately begins cooling with an ice bath and intravenous fluids. Which clinical finding necessitates this immediate treatment?