Researchers combined satellite records of forest loss and land-surface temperature with gridded population data and regional heat–mortality relationships to isolate the health impact of tropical deforestation between 2001 and 2020. Comparing pixels that lost trees with nearby intact-forest pixels, they estimate a deforestation-induced warming of ~0.45°C across cleared areas, distinct from broader climate change. Because 345 million people live in or near these deforested landscapes, even modest local heating translates into a sizable health burden: about 28,330 extra non-accidental deaths per year. Population-weighted warming in affected zones averages 0.27°C; the mortality burden is largest in Southeast Asia (notably Indonesia), followed by tropical Africa and Central/South America. In places that lost forest, deforestation explains roughly 64% of total local warming, and may account for over one-third of total heat-related mortality tied to warming in those locations. The analysis, which uses standard land-surface temperature proxies where air-temperature networks are sparse, includes extensive sensitivity checks and likely underestimates risk: it excludes additional regional spillover warming beyond the cleared pixels and omits the global heat impacts of CO₂ released by deforestation. The core message is direct—tropical forests act as local cooling infrastructure. Where the canopy is removed, temperatures rise and heat deaths increase, making forest protection an immediate public-health intervention as well as a climate and biodiversity priority.