Temperature variations in automobiles in various weather conditions. An experimental contribution to the determination of time of death

From January 1995 through March 2000, temperatures in the passenger compartment of automobiles of different sizes were measured under varying weather conditions (sunshine, cloudy skies, rain) at two locations in eastern Switzerland. During the cold season, the interior temperature rose to 21 degrees C when cars were exposed to sunshine, whereas in summer interior temperature extremes of up to 89 degrees C were recorded. Make, model, and color of the vehicles were of only minor influence.     

Rectal temperature time of death nomogram: dependence of corrective factors on the body weight under stronger thermic insulation conditions.

Ninety-eight test coolings were made under various cooling conditions (moving air, two types of both clothing and covering) on dummies of real masses of 1, 3.3, 9.9, 24.5 and 33.4 kg, respectively, which cool under standard conditions (unclothed, uncovered, still air) like human bodies of 14, 33, 41, 83 and 104 kg, respectively. The results provide evidence of a non-linear dependence of corrective factors of body weight upon the body weight. The dynamics of the dependence increases with the thickness of thermic insulation. Transferred to the use of the nomogram method on bodies, cooling conditions requiring corrective factors between 0.75 (moving air) and 1.3 (rather thin clothing/covering), known from experience on bodies of an average weight, can be used as in the past, independent of the body weight. According to experience the dependence of corrective factors on the body weight must be taken into account in bodies of a very high or low body weight. For that purpose both a simplified table and a formula for computing is given.     

Realization of an adaptive method of simulating the process of temperature change of a cadaver on a microcomputer

Programme based on mathematical model of the process of dead body temperature changing was developed for estimation of postmortem interval. Automatic retrieval of problem solution was performed on programmable microcalculators of "Electronica MK-61" type using adaptive approach. Diagnostical accuracy in case of dead body being preserved in permanent cooling conditions is +/- 3%.     

Rectal temperature time of death nomogram: sudden change of ambient temperature

Cooling experiments on dummies known as body-like cooling were performed with sudden decrease and increase of ambient temperature in the order of 15 degrees C. In the case of a sudden decrease of ambient temperature, a second 'temperature plateau' occurs which is shorter than the known plateau at the beginning of body cooling. The cooling curves can be described mathematically by a three-step procedure based on the two-exponential term of the 'nomogram method'. The second plateau at the beginning of the second cooling phase in sudden decreased ambient temperature requires a lower value of the constant A (1.15) compared with the known value (1.25) at the beginning of body cooling. In the case of a sudden increase of ambient temperature in the order of 15 degrees C no procedure could be found to model the cooling curves mathematically.     

Estimation of the time since death: sudden increase of ambient temperature

This work presents a procedure for the postmortem interval estimation in the presence of a rapid increase of ambient temperature occurred during the cooling phase. The resulting disturbance produced on the cooling curve is proved to obey a two-exponential law and is removed from the actually measured body temperature. This yields a theoretical/modified body temperature, which enables the estimation of the time since death by means of the standard Nomogram method.     

The effect of time after body discovery on the accuracy of retrospective weather station ambient temperature corrections in forensic entomology

Weather station data are used by forensic entomologists to estimate ambient temperatures at body discovery sites. Correlation data from sites may also be collected to correct for site and station differences. This experiment tested the accuracy over time of retrospective weather data correction using linear regression between stations and sites. Temperatures were logged at six hypothetical body discovery sites during a seven-day period for which a hypothetical body lay in situ, and a further four correlation periods. The accuracy of weather data for hypothetical body in situ periods improved after correction in 22 of 24 correlations; however, mean predicted body in situ temperatures for sites differed significantly between correlation periods. Predicted temperatures generally rose with time after body removal, which correlated with rising site temperatures accompanying seasonal change. Therefore, practitioners should be cautious in making correlations if weather patterns during correlation differ greatly from those while the body was in situ.     

The evolution of methods for estimating the time of death from body temperature

A chronological survey is offered of the development of concepts and techniques to use body temperature in the estimation of time since death. For a century and a half, this method has been investigated, though accuracy still cannot be claimed, especially in operational conditions.     

室外温度与室内恒温下EC随死后经历时间的变化

目的在室外环境和室内恒温条件下测定昼夜不同时间猪后腿肌肉电导率(electrical conductivity,EC)值,分析并比较两种环境条件下,EC值随死后经历时间(time since death, TSD)变化的规律。方法取5块即刻屠宰的猪后腿肌肉,均分为两份,随机分成两组,分别置于秋季室外环境和室内18℃恒温环境中。在死后10d内分别于早晚8时(每隔12h)取样,测定其浸渍液EC值。结果两种环境条件下,EC随TSD变化的趋势在整体上是一致的,二者相关性均较好(R2室外=0.971,P室外=0.004,R2室内=0.98,P室内=0.002)。室外环境温度下,肌肉的EC值在白天增长明显,夜间增长不明显,尤其环境温度低于13℃时,出现明显的平台现象,与室内恒温条件下肌肉EC值持续上升的变化趋势有显著的差异。结论无论室外环境温度还是室内恒温下,肌肉EC与TSD的相关性均较好,但在具体分析时,应考虑到夜间低温平台期造成的时间延搁。     

The eye as a chemical indicator of environmental temperature at the time of death

Vitreous humor chemistry profiles were reviewed on 133 autopsied cases in which death occurred outdoors during a six-year period, to determine whether environmental temperature at the time of death influenced chemistry values obtained at autopsy. The glucose concentration and total carbon dioxide content varied inversely with temperature. Values were significantly higher in the winter than the summer months. The mean glucose level was higher in deaths caused by cold exposure than in other deaths occurring in the cold, but individual cases could not be distinguished on the basis of chemistry values. Potassium levels tended to be slightly lower in winter. It was noted that chemistry studies could be used to help determine whether a body found outdoors in winter actually died in a different, warmer environment.