Urban Heat Islands and Climate Vulnerability: Assessing Risks in Rapidly Growing Megacities

Abstract

Urban Heat Islands (UHIs) have emerged as a critical environmental challenge in rapidly growing megacities, driven by uncontrolled urbanisation, loss of green cover, high-density built environments, and increased anthropogenic heat emissions. As global temperatures rise, UHIs intensify local warming, amplifying climate vulnerability for millions of urban residents. This study examines the spatial patterns, drivers, and consequences of UHI formation in megacities, with particular attention to human health risks, energy demand pressures, and socio-ecological inequalities. Findings from recent urban climate research show that low-income and densely populated neighbourhoods experience disproportionately higher heat exposure, exacerbating heat-related illnesses and straining public infrastructure. The paper also analyses how climate change interacts with UHI effects, creating compound risks such as extreme heatwaves, reduced air quality, and heightened mortality. Finally, the study outlines evidence-based mitigation pathways—including urban greening, reflective materials, sustainable building design, and improved climate governance—to enhance resilience in rapidly urbanising regions. The research argues that addressing UHIs is essential for ensuring sustainable urban development, protecting vulnerable populations, and strengthening adaptive capacity in the face of accelerating climate change.