Factors influencing the precision of estimating the postmortem interval using the triple-exponential formulae (TEF). Part I. A study of the effect of body variables and covering of the torso on the postmortem brain, liver and rectal cooling rates in 117 forensic cases.

Brain, liver, rectal and environmental temperatures were continuously monitored under controlled conditions, in 117 forensic fatalities, for up to 60 h after death. Cases were studied either naked (63%) or covered with two blankets (37%). Bodies were classified into fat and thin groups. Statistical analysis and curve-fitting of the data yielded the average triple-exponential formulae for each body site and each body group. The effects of covering of the torso and body parameters such as weight, height, surface area and 'cooling size factor' (Z) on postmortem cooling are assessed and discussed. Results show that covering of the torso has a significant influence on the rate of postmortem cooling, however, there is no good correlation between the body variables and the cooling rate.