Heatstroke admissions to Northeastern and Southern hospitals in the United States from 2016-2020

Background Heatstroke is a life-threatening condition representing the most severe manifestation of heat-related illnesses. Increasing global average temperatures are likely to increase the incidence of heatstroke. Methods We conducted a retrospective, repeated cross-sectional study, using the National Inpatient Sample (NIS) database. We assessed adults hospitalized in the Northeast and South regions of the United States with ICD-10 codes relating to heatstroke. The primary outcome was the number of monthly regional admissions for heatstroke. Multiple logistic and linear regression techniques were used to evaluate secondary outcomes, specifically in-hospital clinical and resource utilization outcomes. Findings Over the five years studied (2016-2020), more heatstroke admissions occurred in the South (n=3, 880) than in the Northeast (n=960). Patients admitted with heatstroke in the South and Northeast regions had similar odds for in-hospital mortality (aOR=0. 84, p=0. 79). The length of stay in the South was nearly one day longer than in the Northeast (aMD=0. 95 days, p=0. 02). There was a trend towards higher charges per heatstroke admission in the South compared to the Northeast (aMD=16, 514, p=0. 07). Admission rates were positively associated with increasing average monthly temperatures - even after controlling for region and season (p<0. 05). Interpretation Heatstroke is a serious condition, and admissions to our nation’s hospitals are likely to increase as our planet gets warmer. Many physiologic, societal, and geographic variables impact vulnerability to heat-related illness. Our society and healthcare systems must actively work towards improving care for those with heat-related illnesses. Funding Not applicable.