Abstract
OBJECTIVES: To evaluate the feasibility and acceptability of an immersive virtual reality (VR) scenario for assessing decision-making in accidental hypothermia resuscitation within a civil-military disaster-management exercise, and to explore neurophysiological signals as hypothesis-generating correlates of decision-making. DESIGN: Cross-sectional observational study. SETTING: A multinational civil-military disaster-management exercise in Bulgaria (September 2025). PARTICIPANTS: Convenience sample of first responders who completed the VR scenario and post-experience questionnaire (n=62; mean age 30.6 years (SD 7.8); 59/62 male (95.2%) and 3/62 female (4.8%); 43/62 civilian (69.4%) and 19/62 military (30.6%)). INTERVENTIONS: Participants completed an interactive 360° immersive VR scenario with multiple-choice decision points covering key steps in accidental hypothermia management. A subsample underwent exploratory neurophysiological monitoring (electroencephalogram (EEG)/ECG) during the scenario. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was decision accuracy across scenario decision points. Secondary outcomes included perceived usefulness, ease of use, presence and physical discomfort. Exploratory outcomes (subsample) included EEG-derived engagement index and frontal alpha asymmetry. RESULTS: Sixty-two participants completed the simulation. Perceived usefulness and ease of use reached the highest median score (7.0 (IQR 6-7.0)), with >95% agreement across items. Decision accuracy across decision points ranged from 37.5% to 85.7%, with lower accuracy in hypothermia-specific algorithm steps compared with general resuscitation actions. In a very small exploratory EEG/ECG subsample, illustrative case-level, event-locked individual traces suggested possible differences preceding incorrect responses (hypothesis-generating only). CONCLUSIONS: Immersive VR was feasible and well accepted for assessing hypothermia resuscitation decision-making in a civil-military exercise. Observed performance highlighted hypothermia-specific decision gaps. Controlled and longitudinal studies are needed to evaluate learning gain and training effectiveness.