The terminal temperature of surfacecooled adult dogs is remarkably constant. If we define the terminal temperature as the rectal temperature at which a dog's heart succumbs either to ventricular fibrillation or to cardiac arrest, we find from the literature the following mean terminal temperatures: 16.5 C, DeBoer et al.1; 18.5 C, Covino et al.2; 18.6 C, Hegnauer,3 and in the present no-treatment group, 19.4 C. Young dogs withstand much lower temperatures. DeBoer1 found that the mean lethal temperature of young dogs was 9.5 C. The present paper describes experiments in which the mean terminal temperature of adult surface-cooled dogs was significantly reduced below those values reported above.
Caranna et al.4 have shown that survival of animals cooled to 25 C and subjected to intracardiac surgery is increased by the infusion of nutrients; therefore, we wished to determine whether a continuous infusion of 5% dextrose would