Three phases of hypothermia development during general anesthesia

Hypothermia during general anesthesia develops with a characteristic pattern. An initial rapid decrease in core temperature results from a core-to-peripheral redistribution of body heat. This is followed by a slow, linear reduction in core temperature that results simply from heat loss exceeding heat production. Finally, core temperature stabilizes, and subsequently remains virtually unchanged. This plateau phase may be a passive thermal steady state, or result when sufficient hypothermia triggers thermoregulatory vasoconstriction. Results are presented as means±SDs.