EFFECTS OF REPEATED EXERCISE REST SESSIONS AT -10-DEGREES-C ON SKIN AND RECTAL TEMPERATURES IN MEN WEARING CHEMICAL PROTECTIVE CLOTHING/

The development of thermophysiological responses during four consecuti ve exercise/rest sessions in the cold was studied in men wearing chemi cal protective clothing and a face mask. Six men repeated four exercis e/rest sessions during 8 h at -10 degrees C. Each session consisted of step exercise (240 W . m(-2)) for 60 min and rest for another 60 min. Rectal and skin temperatures were measured continuously and thermal s ensations were obtained at 30-min intervals. Entering the cold from a warm environment and the onset of exercise resulted in a decrease in s kin temperatures during the first session and the decrement in the tem peratures of the extremities continued for 10-20 min during the follow ing period of exercise. Torso skin temperature was at its lowest durin g the first rest period. After the first session of cold exposure the range and the level of variation in mean body temperature ((T) over ba r(b)) followed a pattern which was repeated until the end of the exper iment. However, the torso skin temperatures increased gradually until the fourth session, while the temperatures of the extremities, in cont rast, tended to decrease up to the third session. In conclusion, the p resent results indicated that although Tb, reflecting the whole body h eat balance, showed a typical pattern of change after the first sessio n (2 h), the torso area was warming until the end of the cold exposure while the extremities continued to cool down up to the third session (6 h), obviously due to a prolonged redistribution of the circulation.