Ajith N Nair, Bhavnidhi Sood, Prashant Anand, Ardeshir Mahdavi
Abstract Heatwaves have emerged as a critical global risk due to their escalating impacts across social, economic, and environmental systems. Globally, heatwave frequency, intensity, and duration have increased markedly, and under a 2.0 °C global warming scenario, severe heatwaves in India could become up to 30 times more frequent by the end of the century. As a tropical, developing country, India faces disproportionately high heat exposure, compounded by rapid urbanisation, socio-economic inequalities, and limited adaptive capacity. This review synthesises multidisciplinary evidence on heatwaves in India using an analytical framework inspired by the Driver-Pressure-State-Impact-Response (DPSIR) paradigm to systematically organise and interpret interactions between physical processes, vulnerability conditions, observed impacts, and governance responses. The review identifies key natural and anthropogenic drivers, including large-scale atmospheric circulation, land–atmosphere feedbacks, climate variability, urbanisation, and land-use change, and highlights reinforcing feedbacks such as soil-moisture depletion and urban heat island effects that intensify extreme heat. It examines spatially and socially differentiated vulnerabilities across regions, populations, sectors, infrastructure, and essential services, demonstrating that heat risk is shaped as much by exposure and sensitivity as by temperature extremes alone. Documented impacts span public health, ecosystems, economic productivity, energy and water systems, the built environment, and sustainability outcomes, with implications for India’s global development commitments. Finally, the study critically evaluates heatwave management in India, including early-warning systems and Heat Action Plans, assessing their effectiveness, limitations, and equity implications, and proposes targeted recommendations to address persistent gaps in heatwave governance and resilience planning under a warming climate.