Estimation of time since death after a post-mortem change in ambient temperature: Evaluation of a back-calculation approach.

The temperature-based "Henssge method" is widely applied for death time estimation. For cases with a sudden post-mortem (pm) change in ambient temperature (e.g., by bringing the deceased into a cooling chamber), a mathematical approach has already been proposed [1] that enables estimation of the time of death by back-calculation of body temperature. This approach was evaluated under clinically controlled conditions. Twenty-five individuals who died in a neurosurgical intensive care unit were brought to cooling storage after approximately 3 h pm. Body temperature was repeatedly measured on the ward and in cooling storage over a period of 9 h pm. Back-calculation of body temperature was carried out on the basis of the proposed mathematical approach for cases with pm changes in ambient temperature; the results were compared to the known body temperatures. In many cases, the back-calculated and true body temperatures differed widely. Bodies regularly cooled down slower after being brought into cooling storage than the back-calculations indicated. The sudden change in ambient temperature could only be addressed roughly by the proposed method of back-calculation. In conclusion, the evaluated approach for addressing pm changes in ambient temperature should only be applied with great caution.