Accidental hypothermia in emergency care: multifactorial triage-based prediction of early critical outcomes in a temperate-climate cohort

Abstract

Background Accidental hypothermia, defined by a core temperature <35 °C destabilizes metabolism, ventilation, and circulation, precipitating malignant arrhythmias or cardiac arrest. We characterized such patients in a Hungarian emergency department and sought early predictors of death or intensive care requirement. Methods In this retrospective cohort (2020–2024) at Semmelweis University, adults with measured tympanic temperature <35 °C were identified. Demographics and Hungarian Emergency Triage System categories were recorded. Severity was graded based on the thresholds of Swiss staging and the Wilderness Medical Society classification. The primary outcome was emergency department death or admission to the intensive care unit. Prognostic performance of triage category, admission temperature, hypothermia severity thresholds, and combined models was assessed with receiver-operating-characteristic analysis. Odds ratios were derived from logistic regression, and separate receiver-operating-characteristic curves were generated for each predictor. Results A total of 131 patients met the inclusion criteria. Median age was 67.0 years (IQR 59.0–75.0); 88 (67.2%) were male. Median admission temperature was 29.3 °C (IQR 26.1–31.4 °C); 47 (35.9%) had severe hypothermia (<28 °C). Median emergency department length of stay was 13.7 h (IQR 9.5–18.9 h). Sixteen patients (12.2%) required intensive care and 28 (21.4%) died before transfer, yielding a 33.6% critical-outcome rate (44/131). Incidence tracked seasonal ambient temperatures, yet environmental temperature itself was not associated with the composite outcome. Triage category predicted critical outcome better than thresholds of either hypothermia-specific scale (AUC 0.683). Adding admission temperature improved accuracy (AUC 0.740, 95% CI 0.644–0.829). Conclusions Despite milder winters, accidental hypothermia still carries substantial early mortality. Integrating admission temperature into a general triage system enhances prognostication and may guide rapid escalation of care. Our findings suggest the need for systematic surveillance, focused clinician education, and targeted resources to protect vulnerable patients in increasingly variable climates.