Evaluating the forehead temperature for estimating the postmortem interval

Estimating the time of death (ToD) and correspondingly the postmortem interval (PMI) is a fundamental aspect of forensic medicine, essential for event reconstruction and legal investigations. Traditional methods based on the body core temperature can be influenced by external and physiological factors, potentially leading to uncertainties. This study explores a non-invasive approach using forehead temperature measurements. It offers several advantages over assessing the body core temperature, including reduced sensitivity to clothing insulation and fat composition of the deceased, making it a promising alternative for forensic applications. Temperature data from 31 deceased individuals were analysed using a double-exponential fitting function, achieving high accuracy with a root mean square error of 0.25 °C and a coefficient of determination (R²) of 0.999, indicating a robust model. Compared to traditional methods, the approach presented in this study helps to minimize the influence of individual body factors, although it may still be affected by environmental factors such as sunlight exposure, varying ambient temperature and airflow. The method performs best for shorter PMIs, likely due to the forehead’s faster cooling compared to the body core. Further research is required to validate its performance under varied conditions and to assess its comparability with established approaches.