The provisions of the Labor Act and its compliance with Directive 203/88 / EC regulate the issue of minimum safety and health conditions by setting a limit on weekly working hours, overtime hours and work schedules (shift work). Work in shifts is impossible to avoid, but it is possible to minimize its negative effects on the physical and psychological state of the worker. Work in shifts is not in line with our natural circadian rhythms, nor in accordance with the life of the social environment. Research carried out should be one of the steps towards recognizing signs of negative effects especially night work for the female population.