To analyze the association between extreme heat and acute-care presentations for various medical conditions among adults in the Chicago area.
Approach:
Study Design: The study analyzed 916,904 emergency department and urgent care encounters among 372,140 adults from May to September between 2011 to 2023, using a 2-stage analytic framework.
Data Analysis: Stage 1 involved diagnosis-specific quasi-Poisson models to identify relevant diagnoses, while Stage 2 used distributed lag nonlinear models to evaluate associations with temperature.
Key Findings:
Extreme heat (≥33.67 °C) was linked to increased acute-care visits for renal and fluid-balance disorders, dermatologic conditions, multiple sclerosis, cannabinoid-related disorders, and a range of injury-related diagnoses.
33 diagnoses met reporting criteria, including significant associations for glomerular disorders, edema, acute kidney failure, and multiple sclerosis.
Among injuries, the highest cumulative estimates were for assault, accidental firearm discharge, and lower-limb burns.
Interpretation:
Renal and fluid-balance disorders were notably affected by extreme heat, consistent with prior evidence of dehydration and renal stress.
Limitations:
The study was limited to adults in 4 Chicago health care systems, affecting generalizability.
The cohort overrepresented Black and West Side patients and underrepresented White and Northwest Side patients.
Residential temperature may not reflect actual heat exposure experienced by patients.
Socioeconomic variables were not included, leading to potential residual confounding.
The study lacked external validation as both analytic stages used the same cohort.
Conclusion:
The findings indicate an association between extreme heat and acute care presentations, particularly for renal and injury-related conditions.
