Assessing heat inequalities through the integration of building morphologies and socioeconomic conditions.

The spatial heterogeneity of the urban heat environment is shaped by building morphology, while socioeconomic disparities dictate residents' exposure to heat stress. However, limited research integrates these factors to assess heat inequalities, which is crucial for identifying vulnerable areas most susceptible to urban heat. Therefore, this study examines heat inequality in six Chinese megacities by mapping neighborhood-level building morphologies, focusing on building density and height and integrating socioeconomic data. The analysis shows that neighborhoods of high density & low-rise (HDLR) and high density & mid-rise (HDMR) experience higher normalized land surface temperatures (NLSTs) compared to others. In contrast, medium density & high-rise (MDHR) and low density & high-rise (LDHR) have the lowest NLSTs. Higher population density and lower NDVI in older neighborhoods lead to more anthropogenic heat emissions and limited cooling, resulting in higher NLST in areas with the same building morphology here. Additionally, NLST generally decreases as house prices rise, with undeveloped areas showing slightly higher NLST due to lower NDVI. Consequently, the neighborhood of HDLR, especially those with older buildings and lower house prices, are the most vulnerable to urban heat in Chinese megacities and we emphasize mitigating this inequality through increased urban greenery.