Do Alternative Cooling Methods Have Effective Cooling Rates for Hyperthermia Compared With Previously Established CWI Cooling Rates?

Clinical Scenario: In the last few years, there have been several studies examining alternative cooling strategies in the treatment of exertional heat stroke (EHS). Morbidity and mortality with EHS are associated with how long the patient's core body temperature remains above the critical threshold of 40.5°C. Although cold-water immersion (CWI) is the gold standard of treatment when cooling a patient with EHS, more recent alternative cooling techniques have been examined for use in settings where CWI may not be feasible (ie, remote locations). Clinical Question: Do alternative cooling methods have effective core body temperature cooling rates for hyperthermia compared with previously established CWI cooling rates? Summary of Key Findings: The authors searched for studies using alternative cooling methods to cool hyperthermic individuals. To be included, the studies needed a PEDro score ≥6 and a level of evidence ≥2. They found 9 studies related to our focused clinical question; of these, 5 studies met the inclusion criteria. The cooling rates for hand cooling, cold-water shower, and ice-sheet cooling were 0.03°C/min, 0.08°C/min, and 0.06°C/min, respectively, whereas the tarp-assisted cooling with oscillation (TACO) method was the only method that had an acceptable cooling rate (range 0.14-0.17°C/min). Clinical Bottom Line: When treating EHS, if CWI is not available, the tarp-assisted cooling method may be a reasonable alternative. Clinicians should not use cold shower, hand cooling, or ice-sheet cooling if better cooling methods are available. Clinicians should always use CWI when available. Strength of Recommendation: Five level 2 studies with PEDro scores ≥6 suggest the TACO method is the only alternative cooling method that decreases core body temperature at a similar, though slower, rate of CWI. Hand cooling, cold showering, and ice-sheet cooling do not decrease core body temperature at an appropriate rate and should not be used in EHS situations if a modality with a better cooling rate is available.