The brain response to indoor thermal comfort: from the thermal perception to the current indoor thermal comfort indices

Perception and assessment of indoor built environments involve intricate neurosensory processes that link receptors to cognitive centres in the brain. Among these sensory perceptions, indoor thermal comfort (ITC) is a vital component of Indoor Environment Quality (IEQ) that significantly influences both unconscious thermoregulation and conscious behaviours. This study critically reviews existing ITC indices used to measure it. A core challenge addressed in this paper arises from the differentiation between ITC and Perceived Thermal Comfort (PTC), reflecting the actual processes of thermal sensation in the human body and nervous system. Our findings highlight that the neural responses to thermal variations involve six distinct brain regions, all of which can be influenced by the thermal environment, thereby affecting the occupants' psychological states. Furthermore, our research underscores the limitations of current thermal indices. To address this, we propose a framework that integrates the impacts of PTC into building performance assessments.