Energy loss due to radiation in postmortem cooling part B: Energy balance with respect to radiation

With the help of the law of Stefan and Boltzmann and a model for the coolin g of exposed skin derived from the data of Lyle and Cleveland [7], the radi ation energy loss E-R can be calculated according to the following formula. E-R(t) = epsilon sigma A(R) (0)integral(t) ([(T-S(0) - T-E) e(-z't) + T-E] - T-E(4)) d t' where epsilon represents the emissivity of the skin (0.98), a the Stefan-Bo ltzmann constant, A(R) the radiating surface area, T-S(0) the skin temperat ure at death, T-E the environmental temperature and Z' = 0.1017 the gradien t of the skin temperature curve. Additionally, an energy loss due to conduction and convection E-C has to be taken into account. Comparing the energy losses due to radiation, conducti on and convection with the decrease E-T of the thermal energy in the body, calculated from mean heat capacity (3.45 kJ/(kg degrees K)), body mass and decrease of mean body temperature, there is a surplus of energy in the very early postmortem period, which can be explained only by an internal source of energy E-I. Alltogether the following balance equation can be formulate d: E-T+ E-I = E-R + E-C Since the body temperature decreases in the early postmortem period, E-I ca n be estimated by: E-I(t) greater than or equal to max (E-R(t) - E-T(t), 0) . The values obtained range up to 500 kJ for a medium sized (175 cm), mediu m weight (75 kg) body at an environmental temperature of 5 degrees C and ar e compatible with estimations of Lundquist [6] for supravital energy produc tion by breakdown of glycogen.