Extreme heat is an escalating public health concern. Although prior studies have examined heat-health associations, their reliance on restricted diagnoses and diagnostic categories misses or misclassifies heat-related illness. We conducted a heat-wide association study to identify acute-care diagnoses associated with extreme heat in Chicago, Illinois. Using 916,904 acute-care visits -- including emergency department and urgent care encounters -- among 372,140 adults across five healthcare systems from 2011-2023, we applied a two-stage analytic approach: quasi-Poisson regression to screen 1,803 diagnosis codes for heat-related risks, followed by distributed lag non-linear models in a time-stratified case-crossover design to refine the list of heat-related diagnoses and estimate same-day and short-term cumulative odds ratios of acute-care visits during extreme heat versus reference temperature. We observed same-day increases in visits for heat illness, volume depletion, hypotension, edema, acute kidney failure, and multiple injuries. By analyzing the full diagnostic spectrum of acute-care services, this study comprehensively characterizes heat-associated morbidity, reinforcing and advancing existing literature.

翻译：极端高温是一个日益严重的公共卫生问题。尽管先前的研究已探讨了热暴露与健康之间的关联，但它们依赖于受限的诊断和诊断类别，导致热相关疾病被遗漏或错误分类。我们在伊利诺伊州芝加哥市进行了一项热暴露全关联研究，以识别与极端高温相关的急症护理诊断。利用2011年至2023年间五个医疗系统中372,140名成人的916,904次急症护理就诊（包括急诊科和紧急护理就诊）数据，我们采用了两阶段分析方法：首先使用准泊松回归筛选1,803个诊断代码的热相关风险，随后在时间分层病例交叉设计中应用分布式滞后非线性模型，以精炼热相关诊断列表，并估计极端高温期间（相较于参考温度）急症护理就诊的当日及短期累积比值比。我们观察到因热病、容量不足、低血压、水肿、急性肾衰竭以及多处损伤的就诊量在当日有所增加。通过分析急症护理服务的完整诊断谱，本研究全面刻画了热暴露相关的发病率，巩固并推进了现有文献。