Deadly Heat Stress to Become Commonplace Across South Asia Already at 1.5°C of Global Warming

South Asia (SA) is one of those hotspots where earliest exposure to deadly wet‐bulb temperatures ( T w >35°C) is projected in warmer future climates. Here we find that even today parts of SA experience the upper limits of labor productivity ( T w >32°C) or human survivability ( T w >35°C), indicating that previous estimates for future exposure to T w ‐based extremes may be conservative. Our results show that at 2°C global warming above pre‐industrial levels, the per person exposure approximately increases by 2.2 (2.7) folds for unsafe labor (lethal) threshold compared to the 2006–2015 reference period. Limiting warming to 1.5°C would avoid about half that impact. The population growth under the middle‐of‐the‐road socioeconomic pathway could further increase these exposures by a factor of ∼2 by the mid‐century. These results indicate an imminent need for adaptation measures, while highlighting the importance of stringent Paris‐compatible mitigation actions for limiting future emergence of such conditions in SA.