Effect of Environmental Temperature on Working Memory in Military Personnel

Background: Working memory is one of the essential cognitive functions. Achieving the highest cognitive performance is especially important in critical jobs such as military and crisis management-related jobs. The thermal environment can cognitive functions. Humans have different thermal sensations in the same fixed temperature environments. Objectives: This study was conducted to determine the effect of thermal environment and thermal sensation on working memory. Methods: Each of 20 male adult participants, physically and mentally healthy aged 19 - 29 years, experienced seven thermal conditions (office room climate: 14°C, 17°C, 20°C, 23°C, 26°C, 29°C, and 32°C) over four months. Before the test, they waited 40 minutes in the room for adaptation. The thermal sensation questions were asked from them, and working memory was measured with the n-back test. Results: In this experiment, 140 working memory data were collected. The relationship between air temperature and working memory was significant in two of six conditions. The relationship between thermal sensation and working memory was significant in all six conditions. Participants had various thermal sensations in the same fixed thermal environment. Conclusions: Thermal sensation significantly affected the working memory of the environment users. Working memory was more related to changes in people’s thermal sensation than changes in ambient temperature. Adjusting the ambient temperature based on the user’s thermal sensation increases cognitive performance and prevents working memory loss.