The effects of indoor ambient temperature at work on physiological adaptation in night shift nurses

Aim: To examine the effects of indoor ambient temperature on thermal comfort, night work tolerance (fatigue, sleepiness and night adaptation) and urinary melatonin in night shift nurses. Background: Night shift induces physical stress and mental stress. Night shift work and ambient temperature are associated with work performance. The working environment must be improved for successful night shift working. However, the effects of indoor ambient temperature on night shift nurses are unclear. Methods: In this crossover study, 20 participants were divided into two groups of 10 and were assigned to work in one of two thermo-controlled environments (23°C vs. 26°C) during two consecutive night shifts. Thermal and humidity sensation vote, night work tolerance, body temperature and urinary melatonin were assessed. Results: There were significant differences between the two groups in thermal sensation and body temperature. There were no significant differences in humidity sensation vote or night work tolerance. Urinary melatonin levels decreased significantly during the second 23°C night shift. Conclusion: A temperature of 23°C may exert a positive effect on night shift adaptation. Implications for Nursing Management: Nurses and nursing managers should assess thermal comfort during night shifts, and improved thermal comfort level should be provided to nurses.