Emergency Department Visits and Temperature: Evidence from Mexico

We estimate the impact of temperatures on emergency department visits using daily data from the universe of public hospitals in Mexico from 2008 to 2022. We find that cold temperatures decrease visits by up to 8.9 percent on the same day, and warm temperatures increase visits by as much as 3.6 percent. Using distributed lag models, we then show that cold temperatures can reduce visits for the next 30 days by up to 16.3 percent. For warm temperatures, contemporaneous and cumulative effects are similar (limited harvesting). These findings suggest that, unlike mortality, temperatures affect the demand for emergency services linearly. Leveraging the granularity of our dataset, we also document significant heterogeneities (e.g., higher sensitivity for children and teenagers) and relevant mechanisms, such as ecosystem dynamics and behavioral changes. Finally, we project that temperature-driven annual emergency department visits will increase by 0.24 percent by midcentury, resulting in an estimated increase of 92 million USD in annual medical expenditures in Mexico.Keywords: Temperature, Morbidity, Mexico, Climate ChangeJEL: I12, O13, Q54