Thermal comfort analysis of car drivers through physiological responses in different cabin environments.

A comfortable cabin thermal environment is vital for driver well-being and safety. To establish quantitative guidelines, this study investigated the relationships between physiological signals and subjective thermal perception under realistic vehicular conditions. We collected thermal sensation and comfort votes (TSV/CSV) from a diverse cohort across a range of cabin temperatures, simultaneously measuring five physiological signals: wrist temperature, electrocardiogram, electrodermal activity, electromyogram, and respiration. Our analysis revealed two key findings: 1) Wrist temperature and specific heart rate variability (HRV) metrics showed strong correlations with both cabin temperature and subjective votes, delineating the physiological basis of thermal comfort. 2) We empirically determined the thermal neutral temperature to be 26.2 °C, with the optimal comfort zone spanning from 23.4 °C to 28.3 °C. These results provide car manufacturers with direct, data-driven evidence for defining occupant-centric climate control setpoints and developing future comfort assessment systems based on physiological feedback.