Abstract: On July 7, 2011, Employee #1, a firefighter with the Bonneville Interagency Hotshot Crew (part of the Bureau of Land Management's fire suppression organization), was battling a wildland fire approximately five miles northwest of Mineral Wells, Texas. The crew had been at this fire site since July 5, 2011 and had been working approximately 12 hours each day. At the time of the incident, the outdoor temperature was approximately 105 degrees Fahrenheit. Employee #1 was "cold trailing", which consists of walking along checking for areas of fire that could be extinguished using hand tools or water carried in portable water bladders. At approximately 3:55 p.m., Employee #1 suddenly collapsed. The on-site EMTs were notified immediately and began CPR. A medical emergency evacuation helicopter with flight nurses aboard and an ambulance were dispatched to the site. Both were at the site before Employee #1 was carried down the mountain to the transport location. The nurses were ferried by truck to meet Employee #1 so that treatment could begin as quickly as possible. They reached Employee #1 and began treatment within about 35 minutes of his initial collapse. Employee #1 was transported to the local hospital by ambulance, but died within about 3 hours. Initial reports indicated that Employee #1's core temperature was approximately 108 degrees. He may have died from heat exhaustion.