Effects of Heat Stress on Cognitive Performance


  • Sara Podgornik University of Ljubljana


Environmental factors, such as heat stress, affect human performance. Increased ambient temperature reduces heat loss from the body, resulting in increased deep body temperature. Such heat-induced physiological strain may cause cognitive impairment, resulting in slower reaction time and an increased number of human errors performed [1]. An understanding of the effect of heat stress on cognitive performance is crucial for improving safety in the workplace. Especially since the increased complexity of industrial and military tasks has increased the level of mental workload required for the completion of these tasks, leading to a higher risk of human error [2].

Hypothesis and Methods

Based on previously conducted studies we hypothesize that heat stress will induce impairment in cognitive performance and thermal comfort and that a ventilated vest will mitigate these impairments due to the enhanced evaporative cooling offered by the vest (portable cooling systems) [3].

Ten male participants will perform a walk on a treadmill, and simulated guard duty in two different conditions. In the first condition, they will be wearing an evaporative cooling vest with the bulletproof vest (to add extra load), whereas in the second condition they will only be wearing the bulletproof vest. During the trial, the following physiological measurements will be collected: gastrointestinal temperature, torso skin temperature, microclimate temperature, relative humidity, and heart rate. Subjective ratings of thermal comfort will also be assessed via questionnaires. Cognitive performance, more specifically reaction time, attention, and executive functions, will be measured using the Trail Making Test and Stroop Test.


Considering the results of previous studies conducted in a real work environment we expect to see impairment of cognitive performance and thermal comfort within each subject in conditions without an evaporative cooling vest that mitigates heat stress. Altogether, attaining a definite conclusion regarding the relationship between heat stress and cognitive performance might be difficult due to task type, exposure duration, skill, and acclimatization level of the individual and gender variable [1].


[1] A. Mazloumi, F. Golbabei, S. Mahmood Khani, et al., “Evaluating Effects of Heat Stress on Cognitive Function among Workers in a Hot Industry,” Health Promot Perspect, vol. 4, no. 2, pp. 240–246, 2014. [2] P. A. Hancock and I. Vasmatzidis, “Effects of heat stress on cognitive performance: the current state of knowledge,” International Journal on Hyperthermia, vol 19, no. 3, pp. 355–372, 2003.

[3] J. Tang, Y. Liu, H. Du et al., “The effects of portable cooling systems on thermal comfort and work performance in a hot environment,” Build. Simul., vol. 14, pp. 1667–1683, 2021.