Abstract

This study explores how temperature-induced hospital crowding influences care trajectories and patient outcomes. Utilizing comprehensive data from Mexico’s largest healthcare subsystem from 2012 to 2019, including emergency, inpatient, and outpatient visits, we delve into the impact of daily temperature shocks on healthcare service dynamics. Our findings reveal a linear increase in healthcare demand reaching a 10% uptick in emergency department visits in the hottest bin compared to average days. While more patients are admitted from ERs into hospitals, the likelihood of an individual patient's admission decreases as temperatures climb, suggesting a capacity crunch in healthcare facilities. This trend of increasing patient triage leads to more severe patients being sent home on hotter days. Furthermore, we observe a deterioration in care quality, reflected in heightened excess mortality rates inside hospitals. Data from death certificates confirm an overall increase in mortality in extreme days. Deaths outside hospitals, in particular, escalate more sharply. Our results shed light on the broader implications of climate-driven hospital crowding.