The methodology compared intermediate mitigation and high-emission Shared Socioeconomic Pathways (SSPs) using Summer Mean Temperature (SMT) as the primary climate driver while excluding complex non-linear exposure-response relationships to ensure model interpretability. Key Clinical Findings of the Study Include:• Accelerated Fatality Rates: The analysis shows that under the high-emission scenario, mortality trajectories documented a dramatically steeper escalation that becomes markedly more accelerated after the mid-century mark. • Pathway Sensitivity: Comparative analysis demonstrated a multi-fold surge in heat-related deaths for the high-emission pathway relative to the more moderate mitigation path, emphasizing the extreme sensitivity of health outcomes to carbon trajectories. • Mitigation Efficacy: Conversely, the intermediate mitigation scenario revealed significantly more moderate and spatially uniform mortality trends across the subcontinent by the end of the 21st century. Heatwave-Related Mortality Across Indian Cities Under Future Climate Scenarios.