Human thermal exposure to extreme heat is a growing health concern and pressing societal problem worldwide that will be exacerbated by climate variability, more frequent and intense heat waves, continued urbanization, and socio-demographic changes towards bigger economic disparities and a growing elderly population. Hazardous heat has wide-ranging adverse effects on people?s performance, health, and well-being, posing a major challenge to the sustainability and livability of cities in the future. The bioclimate or how humans experience heat is driven by complex interactions between urban infrastructure (e.g., streets, buildings, trees) and micro- to global scale climates. The goal of this Faculty Early Career Development (CAREER) grant is to advance understanding of how the built environment impacts heat and human thermal exposure in cities. Bridging the gap between localized field-based work and large-scale, generalizable models, this transformative project will expand beyond the limits of conventional heat research and fundamentally reframe how heat is assessed in urban areas by using radiation-based metrics and indices. New academic-practitioner partnerships with cities will yield co-developed, solutions-oriented research that translates into actionable best practices for infrastructure management and human-centric heat hazard mitigation. This work aligns with NSF's mission to advance public health and well-being. It has the potential to result in broader societal change by informing public policy to make communities more thermally comfortable and walkable, increase heat awareness, build adaptive capacity and community resilience to heat, and potentially reduce the incidence of heat-related illness and death.

The research objectives of this project are to 1) create fundamental knowledge on the complex bioclimatic dynamics in the built environment across the full parameter space of urban forms and materials through extensive field work campaigns; 2) assess human thermal exposure and comfort in cities at unprecedented spatial and temporal scales using an innovative big data and artificial intelligence approach; 3) perform a vulnerability analysis by linking urban ?hot spots? to populations at risk to high heat; and 4) evaluate the bioclimatic efficiency of single and combined heat hazard mitigation strategies such as cool pavements and increased tree canopy cover for current and future climate conditions. The project will use a novel mobile sensing platform (MaRTy) to characterize heatscapes in two US cities (Phoenix, AZ and Los Angeles, CA), understand the non-linear relationship between urban infrastructure and heat, and build the first comprehensive geodatabase of human thermal exposure observations during hot weather across the full parameter space of urban form (configuration and composition), materials, and vegetation. An open-source, radiation-based human thermal exposure model (OpenMRT) will be developed using Street View images and deep learning to quantify experienced heat from a human-centric perspective. OpenMRT will be employed to assess the impact of various urban infrastructure modifications on city-wide human thermal exposure and vulnerability in Phoenix and Los Angeles for current and future climate conditions and urban form scenarios. The education objectives of this project are to 1) broaden the STEM pipeline by recruiting women into engineering, 2) foster interdisciplinarity, and 3) build a community of scholars by implementing a vertically and horizontally integrated education plan. Dissemination of research findings in informal learning settings and through social and traditional media will enhance public literacy around heat, health, and the role of urban infrastructure for cooling. The project also supports the exchange of new knowledge on the thermal impacts of urban infrastructure through convergent education, which engages practitioners and decision-makers from various disciplines to co-create heat mitigation solutions that can be translated into effective policies for urban infrastructure management that are grounded in observational data and modeling to increase urban resilience to heat.