Effect of hypoxic breathing on cutaneous temperature recovery in man

Effect of hypoxia (12% O2) on skin temperature recovery was studied on healthy young men. Forty male volunteers free of any respiratory disorder were randomly selected to participate in the study. Skin temperature, peripheral blood flow, heart rate and end expiratory PO2 and PCO2 were measured. During hypoxic ventilation the peripheral blood flow was reduced and a corresponding drop in skin temperature occurred. This was partly due to hyperventilation associated with hypoxic ventilation. The recovery of skin temperature after cooling the hand for 2 min in cold water (10-12 degrees C) took 5.5 +/- 0.1 min during normal air breathing; during hypoxic ventilation even after 9.1 +/- 0.3 min when the skin temperature recovery curve plateaued, the skin temperature remained about 2 degrees C below control. The results of the present investigation indicate that hypoxia interferes with the normal functioning of the thermoregulatory mechanism in man. Hyperventilation associated with hypoxic ventilation is also partly responsible for incomplete recovery of skin temperature.