Field Studies of Shiftwork: I. Temporal Patterns in Psychophysiological Activation in Permanent Night Workers

Abstract The diurnal variation in body temperature, catecholamine excretion, performance, and subjective alertness was studied among 24 permanent night workers during the 1st, 3rd, and 5th day of their work ' week 'of six nights. Most of the variables showed a significant diurnal pattern with high values during work. Furthermore, the patterns of variation were similar during the three nights of measurement without any observable adjustment over the week. It was therefore suggested that permanent night work might facilitate a more rapid switch over to night work after free days.