Rising temperatures, shifting population: Changes in children’s ambient heat exposure in China

Climate change is intensifying extreme heat worldwide. Concurrently, geospatial distributions of children are shifting due to demographic changes including urbanization. However, how these dual trends interact to shape children’s potential ambient heat exposure remains poorly understood. We introduce a framework that captures where and when children experience heat and accounts for both heat intensity and exposure duration. Comparing 1989–1991 and 2019–2021, we find sharp increases in intensity and duration of Chinese children’s heat exposure. These results show that rising temperatures and shifting populations amplify exposure risks. Our framework offers a simple, low-data-demand way to measure populations’ potential ambient heat exposure, illustrated here for children but applicable to any population subgroup, and supports better-informed strategies to protect children’s health.