Understanding heat-driven health risks: Spatiotemporal dynamics and regional vulnerability in new Mexico

As climate change intensifies, heat-related health risks are expected to increase, arising from complex interactions between environmental and social factors. Although prior research has primarily focused on the effects of extreme heat events on heat-related illnesses, the cumulative impact of prolonged summer heat on all-cause hospitalization trends, as well as its spatiotemporal interactions with key heat-risk factors, remains insufficiently understood. This study addresses this gap by examining the relationship between all-cause hospitalization rates and heat-risk factors, including Wet-Bulb Globe Temperature (WBGT), heat-related social vulnerabilities, and PM2.5, in New Mexico from 2016 to 2022. By integrating a spatiotemporal Bayesian model and Self-Organizing Maps (SOM), we identified regional variations in relative risk and analyzed how these factors influenced hospitalization patterns over time and space. Results show that WBGT only becomes positively associated with hospitalizations after considering heat-related social vulnerabilities. Despite declining hospitalization rates over the study period, the increasing relative risk of hospitalization may reflect underlying healthcare access inequalities. SOM clustering highlights distinct regional patterns, where some counties are more influenced by environmental factors while others are driven by heat-related social vulnerabilities. As a result, our findings highlight the need for geographically differentiated interventions that reflect the evolving impact of heat-risk factors, enabling more effective and equitable resource allocation based on each region's dominant drivers of risk.