The authors propose a modification of the Bayes—Wald—Gubler mathematical method designed for differential diagnostics that extends the possibilities of computer-assisted calculations and simplifies their performance. The practical application of the proposed modification is illustrated by differential diagnostics of the causes of death at low environmental temperature including lethal hypothermia, sudden death from cardiac diseases, mechanical asphyxia, mechanical injury, and acute alcoholic intoxication. The most informative histological features are described and diagnostic coefficients are presented. The method of calculations in the framework of the Microsoft Excel software package are proposed. The results obtained with the help of the standard and modified Bayes—Wald—Gubler mathematical method are compared, their effectiveness for the purpose of combined diagnostics of the causes of death is demonstrated.