In determining whether or not the victim was dead at the start of the fire, evidence of respiration during the fire is crucial. Unless the victim was suddenly engulfed by intense heat, respiration will be evidenced by the inhalation of smoke, other combustion products, and sometimes accelerants. The autopsy must determine whether death resulted from natural causes prior to or in the course of the fire or was produced by injuries unrelated to the fire. This involves distinguishing bodily damage caused by the fire from that caused by sickness or inflicted injuries. The pathologist is also instrumental in helping identify the victim through such evidence as physical features, surgical remnants, dental characteristics, and X-ray evidence of congenital deformities. When the victim dies in the hospital after the fire, the extent of tissue damage and subsequent medical complications arising therefrom are important in the cause of death. The toxicological examination of fire victims helps establish whether the victim was dead or alive (evidence of inhalation of carbon monoxide, accelerants) when the fire started and the cause of death (carbon monoxide levels and the presence of other toxic combustion products). Photographic illustrations.