Assessing cold exposure risk during cold waves in Beijing using high spatiotemporal resolution population data and temperature variations.

In the context of global warming, the frequency and intensity of extreme weather events are intensifying. Although cold waves have significant impacts on human health, related research remains insufficient. This study integrates high-resolution population dynamics and temperature data to assess cold exposure risks during cold waves in Beijing, addressing a critical research gap in urban public health. We have developed an advanced cold exposure risk assessment framework aimed at uncovering the potential health threats posed by winter cold waves to urban residents. Our findings reveal that population movement between urban and suburban areas significantly affects cold exposure risks, with nighttime dynamics exacerbating exposure levels. Specifically, nighttime population dynamics substantially exacerbate cold exposure levels, while daytime population dynamics, due to the urban heat island effect, to some extent reduce cold exposure risks. Additionally, compared to traditional average temperature metrics, dynamically population-weighted temperatures more accurately reflect actual cold exposure risks. The findings of this study provide valuable insights for urban public health management, emphasizing the importance of considering population mobility in public health strategies for responding to extreme weather events.