Investigation of thermal penetration from the fire scene into the deceased fire victim

• Research on unique dataset facilitated by the burning human cadavers. • Acquisition of thermal penetration data beyond the dermal layer of skin into the body. • Data and analysis from real fire scenes from ignition through to suppression. • Research developed focusing on enhancing investigation of the fatal fire victim. • Highly statistical significance between flashover with internal body temperature rise. Investigating fatal fires is a complex multi-disciplinary undertaking, with victims considered to be a fundamental part of the evidence. This study investigated thermal penetration into human remains with the aim of extending the results to the assessment of the fatal fire victim. Data was collected during the burning of 15 unembalmed bodies in years 2017–2019 with the San Luis Obispo Strike Team (SLOFIST) on their annual Forensic Fire Death Investigation Course (FFDIC). Cadavers were placed within a scene of individually built compartment rooms to simulate accidental and intentional fires. Thermocouples were placed within the compartments at ceiling/mid/floor levels and within the thoracic cavity of the deceased which facilitated analysis of thermal transition through phases of fire development from ignition to suppression. Radiant heat flux data enabled investigation of the relationship of the thermal environment and internal body temperature rise in kW/m 2 . A statistically significant relationship between ceiling radiant flux and internal body temperature was identified in the thermal penetration of the body at p ≤ 0.041, and a highly statistically significant correlation of p ≤ 0.001 between internal body temperature rise and the fire development phenomenon of flashover. The effect size for this relationship (88%) indicates that a large proportion of internal body temperature rise in fire victims is accounted for by exposure to the fire phenomenon of flashover