Hypothermia is defined as a core body temperature of less than 35 °C (95 °F). Prolonged exposure to a cold operating room, evaporative heat loss from the respiratory tract, infusions of cold fluids, and loss of heat production secondary to shock cause decreased core temperatures in most patients with trauma.

Strategies to reduce the risk of hypothermia include covering skin surfaces that are not in the surgical field with warm forced air blankets (to reduce convective and radiant heat loss), humidifying inspired gases (to reduce evaporative heat loss from the lungs), using a warming device for fluids and blood, and increasing the room temperature.