An anti-hypothermia composition is provided, in particular an anti-hypothermia composition that prevents hypothermia caused by general anesthesia during surgical operations. The composition prevents hypothermia by preventing the decrease in the biological function of patients and correcting acidosis. Specifically, the anti-hypothermia composition is a preparation containing a bicarbonate ion and provided in the form of an infusion fluid. The infusion fluid preferably contains sodium bicarbonate as a major component that serves as a source of the bicarbonate ion, along with each or a combination of other electrolytes, glucose and amino acids.