Hypoxia awareness and symptom dynamics under aviation-related simulated exposure.

Introduction: Hypoxia poses a significant risk in aviation and other safety-critical domains, yet individual awareness and perception of hypoxic states remain highly variable. This study investigated subjective symptom perception, continuous self-assessment, hypoxia recognition, objective performance, and physiological responses during experimentally induced hypoxia. Methods: Twenty-three participants completed two experimental sessions in a within-subject design: a control condition and a hypoxia condition. Subjective symptoms were assessed using a post-exposure questionnaire, complemented by continuous ratings of overall feeling, concentration, and breathing. Objective performance was evaluated using a Stroop test and a mental rotation task, while physiological response was quantified via peripheral oxygen saturation (SpO Results: Hypoxia induction was robust across all participants, with significant reductions in SpO₂ metrics under hypoxia. While no individual symptoms reached statistical significance after correction for multiple comparisons, several hypoxia-related symptoms showed consistent directional trends and approached statistical significance. Continuous subjective ratings were significantly lower under hypoxia, with breathing demonstrating a pronounced temporal deterioration. Hypoxia recognition occurred more often during hypoxia than during control. No significant effects were observed in objective performance measures. Discussion: These findings suggest that hypoxia primarily affects physiological state and subjective experience, with breathing-related sensations showing the clearest temporal changes among the subjective measures and potentially contributing to hypoxia awareness within the present experimental paradigm.