In very cold weather, a significant mechanism for heat loss by the human body is energy expended in warming the air taken into the lungs with each breath.
(a) On a cold winter day when the temperature is -20oC,what is the amount of heat needed to warm to internal body temperature(37°C) the 0.50 L of air exchanged with each breath? Assume that the specific heat capacity of air is1020 J /(kg.K) and that 1.0 L of air has a mass of 1.3 g.
(b) How much heat is lost per hour if the respiration rate is 20 breaths per minute?