Air pollution and extreme heat are adverse health risks, especially for aging populations. However, the associations between air pollution, heat exposure, and cognitive impairment remain unclear. This study examines these associations in China and compares the period before and during the COVID-19 pandemic. We found that higher temperature, CO2, PM2.5, and O3 concentrations were associated with lower cognitive function. Although the interactive associations of air pollution and temperature were not significant, we found that temperature might be a more harmful risk for cognitive impairment than air pollutants. Further analysis reveals that during the COVID-19 the harmful influence of air pollution on cognition fades away, while temperature-related cognitive impairment remains the same. This finding suggests the importance of environmental policies to reduce air pollution and climate issues for public health.
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