Fig. 1

Flowchart of patient enrollment and group allocation. A total of 511 patients were enrolled from 55 hospitals between 2008 and 2024. After excluding 97 patients under 18 years old, 89 patients with pre-existing comorbidities prior to heatstroke onset, and 35 patients with more than 30% missing data, 290 patients were included in the study. These included patients were further divided into two groups: CHS and EHS.