Can temperate-water immersion effectively reduce rectal temperature in Exertional heat stroke? A critically appraised topic

Clinical Scenario: Exertional heat stroke (EHS) is a medical emergency which, if left untreated, can result in death. The standard of care for EHS patients includes confirmation of hyperthermia via rectal temperature (T_rec) and then immediate cold-water immersion (CWI). While CWI is the fastest way to reduce T_rec, it may be difficult to lower and maintain water bath temperature in the recommended ranges (1.7°C-15°C [35°F-59°F]) because of limited access to ice and/or the bath being exposed to high ambient temperatures for long periods of time. Determining if T_rec cooling rates are acceptable (ie, > 0.08°C/min) when significantly hyperthermic humans are immersed in temperate water (ie, ≥ 20°C [68°F]) has applications for how EHS patients are treated in the field. Clinical Question: Are T_rec cooling rates acceptable (≥0.08°C/min) when significantly hyperthermic humans are immersed in temperate water? Summary of Findings: T_rec cooling rates of hyperthermic humans immersed in temperate water (≥20°C [68°F]) ranged from 0.06°C/min to 0.19°C/min. The average T_rec cooling rate for all examined studies was 0.11±0.06°C/min. Clinical Bottom Line: Temperature water immersion (TWI) provides acceptable (ie, > 0.08°C/min) T_rec cooling rates for hyperthermic humans post-exercise. However, CWI cooling rates are higher and should be used if feasible (eg, access to ice, shaded treatment areas). Strength of Recommendation: The majority of evidence (eg, Level 2 studies with PEDro scores ≥5) suggests TWI provides acceptable, though not ideal, T_rec cooling. If possible, CWI should be used instead of TWI in EHS scenarios.