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 degrees C, 25 degrees C, and 30 degrees 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 degrees 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 degrees 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.