Unveiling Dynamic Heat Exposure Patterns: The Intersection of Human Mobility and Environmental Heat Metrics Using Mobile Phone Data in Urban Areas

Cities are increasingly vulnerable to extreme heat events due to climate change, particularly in densely populated urban areas where heat exposure is intensified by the urban heat island effect. Traditional assessments of heat exposure often rely on static metrics, such as fixed thermal environmental data or residential population maps, which fail to account for the dynamic nature of human mobility. It remains unclear whether human mobility exacerbates or alleviates urban heat exposures of populations in cities, especially in high-density urban areas. This study integrates anonymized mobile phone location data with environmental heat indices to analyse spatiotemporal heat exposure patterns in Singapore. By analysing human mobility patterns with mobile phone data at a fine-grained spatial resolution, we identify hotspots of human activity and heat exposure during specific times of the day, such as work hours and evening commutes. The results highlight significant differences between static and dynamic heat exposure assessments, emphasizing the critical role of mobility in shaping the spatial-temporal patterns of heat exposure. This work provides practical guidance for urban climate adaptation, including the strategic placement of heat shelters, prioritization of urban greening in activity hotspots, and improved zoning policies. Our findings also contribute to enhancing urban resilience and public health outcomes in response to the challenges of climate change.