Heat Waves Linked to Surge in ER Visits for Skin, Kidney, and Injury Issues
A study of over 900,000 emergency room and urgent care visits in Chicago found that on days with temperatures of 92.6°F or higher, there were increases in many health problems, including kidney issues, skin conditions, varicose veins, and even accidental gunshot wounds. The researchers noted that some conditions doubled or tripled, with gunshot wounds jumping more than 30-fold. Experts say the findings highlight underestimated health risks from heat waves.
The Chicago-based analysis examined over 900,000 emergency and urgent care records spanning more than a decade, comparing illness patterns on days at or above 92.6°F against cooler periods. Rather than searching only for explicit heat-related diagnoses, researchers scanned broadly for any condition that became more frequent during hot weather, revealing unexpected spikes in kidney disorders, skin complaints, venous issues, and even assault-related injuries. The study's demographic skew toward Black patients and women was noted as a strength, since those groups are frequently underrepresented in medical research.
Experts emphasized that heat-related illness is likely undercounted when studies rely solely on explicit heat codes like heat stroke. The findings reinforce that heat waves carry consequences beyond mortality, including a broad range of nonfatal health problems that strain emergency systems. With heat waves growing more frequent and intense, researchers stressed that these patterns represent real, measurable effects on community wellbeing and healthcare capacity.
This research could reshape how communities and healthcare systems prepare for extreme heat, shifting focus beyond classic heat stroke toward a wider array of conditions that surge during hot days. Emergency departments in warming cities may face increased patient loads from unexpected sources, potentially straining resources and raising healthcare costs. Vulnerable populations, including those with preexisting kidney or vascular conditions, could be disproportionately affected. Public health messaging may need to broaden, encouraging preventive measures during heat events rather than waiting for severe symptoms to appear.