Computational models of human response to urban heat From physiology to behaviour

Understanding human response to the dynamic urban thermal environments is crucial for effective adaptation to a changing climate and the preservation of health and well-being of an ever urbanizing humanity. This thesis presents a comprehensive set of empirical studies, as well as mathematical and computational models of human response to outdoor thermal environments on the individual level. Human response to the thermal environment is considered on three interacting levels: physiological, perceptional and behavioural. On the physiological level, an advanced system dynamics model of thermal regulation is built and calibrated for a wide range of dynamic thermal environments. We report an empirical study of pedestrian walking speeds in Singapore and demonstrate computationally that Singaporeans incur additional heat stress due to elevated pace of life. To analyse and quantify the behaviour of pedestrian sun avoidance, a controlled experiment with human participants in a natural outdoor environment is considered. We propose a novel hierarchical model of path choices to estimate an individual's perceived effort of walking under the sun. This model provides the means to study and predict pedestrian behaviour in complex urban environments. In addition, we combine the models of human thermal regulation and innate immune system to identify regimes of heat exposure and activity intensity, which can positively or negatively impact the performance of the immune system. The approach of multi-level modelling of complex human-environment interaction, demonstrated in this thesis using an example of thermal environments, can be adopted to comprehensively study human response to other environmental stimuli.