Abstract: Heatwaves are no longer episodic extremes but are increasingly becoming a structural feature of India’s climate landscape. Globally, nearly half a million people die each year from heat-related causes, with Asia accounting for 45 percent of these deaths . Despite the apparent acclimatization to high temperatures in tropical countries, India is experiencing unprecedented mortality linked to heat stress, particularly among vulnerable populations. This discussion provides a detailed exploration of the science of heat-related illness, systemic gaps in data and policy, occupational vulnerabilities, and the evolution of India’s heat governance. Drawing on evidence from mortality patterns, heat action planning, and temperature data, the discussion highlights how climate adaptation can be designed and implemented to build resilience.