Prioritizing heat adaptation measures across Indian cities: a benefit-cost analysis

Although deaths and economic losses from heat are rising globally, heat stress remains a “hidden hazard” due to measurement and valuation challenges. In India, cities are implementing Heat Action Plans, combining cooling measures like urban greening and cool roofs with health interventions such as early warning systems and shifting work hours. However, there is limited understanding of which actions are most effective. Using high-resolution climate modeling, we developed heat risk maps for Lucknow, Chennai, and Surat. We further modeled health and economic losses under a ‘no intervention’ scenario and estimated adaptation strategies’ costs and benefits. Our results show that, by 2050, heat-related deaths could rise by one-third, and productivity losses could affect 2–4% of the economic output. Among adaptations, early warning systems show the greatest return on investment (50:1), while urban greening has a strong benefit-to-cost ratio (3:1), highlighting the need to prioritize these strategies in Indian cities and beyond.