The simultaneous effect of ambient temperature and light intensity on performance: A cross-sectional study

Aims: Environmental conditions affect workers health and performance. The present study aimed to investigate the simultaneous effect of ambient temperature and light intensity on human error. Materials and Methods: This cross-sectional study was conducted on 50 students from Shiraz University of Medical Sciences. Each participant performed 9 tests in 5 min at 3 different temperatures (20°C, 25°C, and 30°C) and 3 lighting conditions (50, 500, and 1000 lux). The participants were asked to select a text randomly. Participants asked to read the text in just 6 min and identify the mistakes. In each step, the number of remaining lines, number of spelling mistakes found, and task completion time were estimated. Results: There was no significant relationship between the temperature and the number of remaining lines, the number of spelling mistakes, and the task completion time (P > 0.05). However, the relationship between different light intensity and the number of remaining lines and number of spelling mistakes was statically significant (P < 0.05). At a lighting of 500, 1000 lux, and a temperature of 25°C, male subjects performed better. Unlike men, women's performance was not affected that much by the light intensity and only declined slightly in the 1000 lux and at 20°C. Conclusions: The results showed that light intensity could be important to create a suitable environment for reducing human error. If the temperature could not increase in an environment due to the nature of a job or economic issues, reducing human errors could achieve by increasing light intensity.