Heatwave-attributable Parkinson’s mortality is projected to increase by the 2080s in China under a high-emissions scenario

The convergence of rapid population aging and heatwaves poses a growing threat to neurological health, particularly for people with Parkinson’s disease. Here we analysed national death records of 59,384 older adults with Parkinson’s disease in China (2013–2020) using a time-stratified case-crossover design to quantify heatwave-associated mortality risks. We then combined these estimates with climate and demographic projections and applied a counterfactual decomposition framework to disentangle the contributions of climate warming, population aging, and adaptation. We found that, without adaptation, heatwave-related deaths could increase by nearly elevenfold by the 2080 s. Population aging drives most of the absolute increase, whereas climate warming amplifies the growth over time. Effective adaptation could prevent up to three-quarters of these excess deaths. These findings highlight a critical policy window before the 2030 s and provide a generalizable framework for assessing climate-related health risks in aging populations. In China, heatwaves could raise Parkinson’s-related deaths nearly elevenfold by the 2080 s, and aging of populations is one of the main drivers, according to a time-stratified case-crossover analysis of 59,384 deaths data and climate–demographic projections.