Walking Under Extreme Heat: Considering Pedestrian Thermal Comfort in the Redevelopment of Historical Urban Areas with Hot-Humid Climate

Ensuring comfortable walking environments is essential for promoting healthy lifestyles and supporting active ageing, especially in densely redeveloped urban cores. However, thermal comfort during walking remains underexplored, a concern heightened by increasingly frequent extreme heat events. This study addresses this gap by presenting findings from a series of field experiments examining how microclimate conditions in redeveloped urban settings influence thermal comfort among older and younger adults. Participants walked through various built environments under very hot conditions, which enabled simultaneous collection of microclimate data and physiological responses, alongside self-reported thermal sensations.

Physiologically equivalent temperatures (PET) were then calculated across these different settings for both age groups, providing a quantitative basis for comparing thermal experiences. Results reveal that urban environments differ in their effectiveness at mitigating heat stress. While PET variations account for most changes in younger adults’ thermal sensations, older adults exhibit greater sensitivity to the characteristics of the built areas and green spaces. The study also explores current redevelopment policy in Hong Kong and discusses how it may reshape thermal environments in historical neighbourhoods, ultimately influencing pedestrian comfort. Taken together, these findings underscore the importance of systematically assessing microclimate conditions in urban redevelopment projects—particularly for areas with large senior populations—and highlight the need for design interventions, such as improved streetscape configurations and baseline tree canopy coverage, to ensure more comfortable and health-promoting walking experiences.