Phase Shifts Of The Human Circadian System And Performance Deficit During The Period Of Transition

At periodic intervals throughout the biological day, biomedical assessments were made for a week prior to jet flight to Manila, for 8 days of layover at Manila, and for a week following return. The rapid translocation effected primary phase shifts as follows: for rectal temperature and heart rate, 4 days; for palmar evaporative water loss, 8 days. The return flight effected a 1-day phase shift. Behavoral integrity was degraded, although to a lesser extent after return. Duration of behavioral impairment was much shorter than the lag time of physiological phase shifts. (Author).