Abstract: At approximately 10:00 a.m. on August 5, 2002, Employee #1 was working for a plumbing contractor and inside a 16 ft deep walk-in freezer of a restaurant. He was using a M. K. Diamond concrete cutting saw, Model Number 9816H, powered by an 8 hp Honda gasoline engine, to cut the concrete floor. After approximately 30 minutes at the task, his employer brought in two fans, directed them at the gas engine, and then left. Employee #1 continued the concrete cutting operation, moving toward the back of the freezer. At approximately 1:00 p.m., he became nauseated and felt faint. He stopped work and went outside to lie down. After an hour of rest, his employer suggested he go home and Employee #1 drove there himself. At 4:00 p.m., his family took him to the hospital, where he was admitted for treatment of carbon monoxide poisoning. Employee #1 was released after three days of treatment.