Overview

• Two years of heatwave exposure was associated with roughly 8–12 extra days of biological age, with about nine days added for every four additional heatwave days.
• Each interquartile increase in cumulative heat exposure (about 1.3°C) corresponded to a 0.023–0.031‑year rise in biological age, indicating dose–response effects.
• Manual workers, rural residents, and people in communities with fewer air conditioners showed the largest aging impacts, pointing to occupational and socioeconomic disparities.
• Researchers analyzed 24,922 adults’ medical screening data from 2008 to 2022 to estimate biological age from organ function, inflammation, blood pressure and other tests.
• Although some adaptation over time was observed, the adverse effect persisted, and the authors note limits in cohort representativeness and individual exposure data, underscoring the case for targeted heat resilience policies.