Influence of the Journay's Time of Day on the De- and Resynchronization of the 24-Hours-Rhythm of Body Temperature After Transatlantic Flights.

The influence of a time-shift of six hours on the 24-hour rhythm of body temperature was investigated in a group of 8 students in Germany and the U. S. A. by measuring their rectal-temperatures after transatlantic flights. The temperatures were taken continuously over the first 6 days and on days 8 and 13 after an East-West flight and after a West-East flight. In contrast to previous studies in which the West flight was day-flight, the East-flight a night-flight, both flights in this case were day-flights. The time of resynchronization after the East-West flight ran up to seven days, the time after a flight in the opposite direction up to ten days.