Abstract: At approximately 2:18 p.m. on August 11, 2003, Employee #1, a prison inmate firefighter, was participating in a training orientation and acclimatization hike. The prescribed hike was to take place on an established trail of approximately one hour in duration and two miles long involving moderate to steep pitches in the terrain. Employee #1 received initial firefighting training on August 6, 2003, with a cadre of 13 other inmates. Employee #1 had received his initial complement of firefighter personal protective equipment and had attended a briefing relating to hydration and heat stress in the morning. Employee #1 collapsed and died due to cardiac arrest brought on by heat stress.