A study of the shape of the post-mortem cooling curve in 117 forensic cases

The shape of the post-mortem cooling curve is described and its theoretical aspects are summarised. The concepts of the "infinite cylinder" and the "initial temperature plateau" are explained and their practical implications are discussed. Results of the study of the shape of post-mortem cooling curves for the brain, liver and the rectum of 117 cases are given. The bodies were monitored either naked or covered with blankets. For each case, temperatures of the three body sites and the environment were monitored soon after death and up to many hours post-mortem. Empirically derived three-exponential formulae were used in this study. The cooling curves for the three body sites were found to be of compound shapes and the slopes of the curves vary throughout the monitoring period. The "initial temperature plateau" was found on average in 22% of all cooling curves with the plateau incidence being significantly highest in the rectal curves (27% of rectal curves compared with 7% of brain and liver curves, P<0.1%). The effect of body sites, body build and covering of the torso on the occurrence of the plateau is assessed and discussed.