Impact of Heat Stress on Individual Cognitive States: Utilizing EEG Metrics in Immersive VR-Based Construction Safety Training

As global warming continues, safeguarding the health and safety of construction workers in extremely hot environments becomes imperative. Real-time and quantitative assessment of workers' cognitive states affected by heat stress is essential. Previous studies, which relied mainly on cognitive performance tests and subjective questionnaires, lacked the capability for real-time tracking of individual cognitive states. The analysis of physiological responses also faced challenges in quantitative evaluation of individual cognitive states. To address these issues, this study proposed a reliable and quantitative approach to explore the negative impact of heat stress on cognitive states such as attention, mental fatigue, and emotion, using electroencephalogram (EEG) metrics in immersive virtual reality (VR)-based construction safety training. This study recruited 20 volunteers, divided evenly between an experimental group exposed to extreme heat (36°C/70%) and a control group in moderate heat (26°C/45%). All participants experienced simulated hazardous working conditions across four distinct VR training scenarios. The findings revealed significant differences in attention control, fatigue, and arousal between the two groups, demonstrating that extreme heat impairs workers' attention, increases fatigue, and heightens arousal. These conditions could potentially increase unsafe actions and accident rates, posing risks to construction worker safety. The identified EEG metrics provide a strategy for the real-time and quantitative evaluation of workers' cognitive states under heat stress. Furthermore, it is expected to develop a heat stress monitoring and diagnostics framework integrating VR and augmented reality (AR) technologies to enhance worker safety in extremely hot environments.