To evaluate the prognostic value of routine coagulation tests for patients with heat stroke.

This was a multi-center retrospective study. Patients who arrived at the hospital <24 h after the onset of Heat Stroke (HS) were included. The routine coagulation variables were detected within 24 h after the onset, including the lowest platelet count (PLC).

60-day mortality rate was 20.9%. The median Prothrombin Time–International Normalized Ratio (PT-INR) of the non-surviving patients was significantly higher than that of the survivors (P < 0.01). The median Activated Partial Thromboplastin Time (APTT) in non-surviving patients was significantly higher than in the surviving patients (P < 0.01). A Cox regression analysis revealed that 60-day mortality was associated with PT-INR (P = 0.032) and APTT (P = 0.004). The optimal PT-INR point for predicting 60-day mortality rate was 1.7. The optimal APTT point for predicting 60-day mortality was 51.45. Patients with increased PT-INR (≥1.7) levels had, overall, a significantly reduced survival time (P < 0.01). Patients with elevated APTT (≥51.45) also had a decrease in survival time (P < 0.01). The prognostic scoring, with increased PT-INR (≥1.7) and prolonged APTT (≥51.45) at one point each, was also demonstrated to be useful in predicting 60-day mortality. Patients whose temperature fell to 38.9 °C within 30 min had significantly lower levels of PT-INR and APTT within 24 h than those who took longer to cool down.

A prolonged APTT and elevated PT-INR within 24 h are independent prognostic factors of 60-day mortality in HS.