Thermal injury due to normal body temperature.

BY MEASURING THE RATES OF THERMAL INJURY OF HAMSTER CELLS IN CULTURE AT VARIOUS TEMPERATURES WE HAVE FOUND THE FOLLOWING: (1) The number of cells surviving heat injury declines exponentially with time with a characteristic rate constant for each temperature. (2) The temperature dependence of the rate constant follows an Arrhenius law from 46 through 41 C. (3) Extrapolation of the Arrhenius curve to 37 C indicates that over 0.2% of cells are irreversibly lost from the proliferating population each hour as a result of heat injury due to physiologic temperature. (4) The effective activation energy for the thermal destruction of the proliferative capacity of a cell is only 8 eV, which is equivalent to the rupture of less than 50 hydrogen bonds. (5) It is possible to calculate from the Arrhenius law the theoretic upper temperature limit for growth of a cell population. For the cells used in this study, the theoretic limit is 40.6 C.