Geographic Context and Differences in Perception of Extreme Heat Risks among Vulnerable Communities

Abstract Growing concern over the impacts of extreme heat has led to increased attention on enhancing the effectiveness of public health interventions. This paper addresses the intersecting challenges of reaching vulnerable populations in distinct geographic contexts and understanding their beliefs and attitudes about heat risk. Specifically, it reports how social and behavioral approaches can inform public health interventions for vulnerable groups using an expanded theory of planned behavior (TPB). The standard components of the TPB, which include an individual’s attitude toward taking protective measures, subjective social norms regarding the risk, and perceived behavioral control in mitigating that risk, are supplemented with additional constructs relevant to heat risk communication. These include perceived severity and susceptibility to heat impacts, adaptation behaviors, and the perceived value and comprehension of heat warning information. A cross-sectional study ( N = 273) was administered across four locations in the central Midlands region of South Carolina, United States, to include different vulnerable populations, including low-income individuals, African Americans, the unhoused, and Spanish speakers in both urban and rural settings. Hierarchical regression and moderation analyses demonstrate that the predictive power of TPB variables and the strength of specific constructs and relationships within the model, particularly perceived behavioral control, vary significantly across geographic locations. These findings highlight the contextual nature of behavioral intentions and the influence of geographic, community-specific, socioeconomic, social, and structural factors, including variations in physical heat exposure and access to support structures, in shaping those intentions. In addition, the study introduces an exploratory, place-based framework to aid interpretation of how vulnerability and access to community support help explain observed differences in the significance of TPB constructs across sites. Significance Statement This research contributes to efforts to improve the overall effectiveness of public health heat risk communication within public health interventions for vulnerable populations. The findings show significant differences across four locations in the factors that motivate people to take actions to avoid heat risks. The research contributes to the growing body of work on heat risk behaviors by demonstrating the importance of integrating geographic, social, structural, and socioeconomic contexts with demographic data in influencing health-related decision-making. The findings suggest that public health interventions should enhance efforts to address the unique context of communities with attention to three actions: increasing perceived behavioral control, addressing disparities in physical exposure and access to support structures, and leveraging social norms to create more resilient and proactive responses to heat-related risks.