The Science of Patient Warming

Phases of Hypothermia During Anesthetic Induction

Phase 1:  Rapid decline of body temperature in the first hour because of redistribution of warm blood to the periphery where it is lost through the skin by radiation and convection.

Phase 2: Slower linear decline in body temperature in the next two hours because of heat loss exceeding internal heat production.

Phase 3: Body temperature stabilizes over the next three to four hours.