Is dense or sprawl growth more prone to heat-related health risks? Spatial regression-based study in Delhi, India

•Comprehensively assessed the heat-related health risk (HRHR) at ward level in Delhi for 2001 and 2017.•The direct linkages between urban morphologies/ landscape metrics and HRHR were established by adopting spatial auto-correlation and spatial regression modeling.•High built-up density positively correlated with elevated HRHR.•Larger vegetation patches surrounded by dense built-up have less cooling efficiency during the night, hence not able to reduce HRHR.•Spill-over effects found as most prominent than direct effects.•SDM found most fitted among the adopted spatial regression models.