Tarp-Assisted Cooling as a Method of Whole-Body Cooling in Hyperthermic Individuals

• Published in: Annals of emergency medicine 2017-03, Vol.69 (3), p.347-352
• Main Authors: Hosokawa, Yuri, PhD, ATC, Adams, William M., PhD, ATC, Belval, Luke N., MS, ATC, Vandermark, Lesley W., PhD, ATC, Casa, Douglas J., PhD, ATC
• Format: Article
• Language: English
• Subjects: Adult; Body Temperature; Cross-Over Studies; Cryotherapy - instrumentation; Cryotherapy - methods; Emergency; Female; Fever - therapy; Humans; Male; Young Adult
• ISSN: 0196-0644; 1097-6760
• DOI: 10.1016/j.annemergmed.2016.08.428

Study objective We investigated the efficacy of tarp-assisted cooling as a body cooling modality. Methods Participants exercised on a motorized treadmill in hot conditions (ambient temperature 39.5°C [103.1°F], SD 3.1°C [5.58°F]; relative humidity 38.1% [SD 6.7%]) until they reached exercise-induced hyperthermia. After exercise, participants were cooled with either partial immersion using a tarp-assisted cooling method (water temperature 9.20°C [48.56°F], SD 2.81°C [5.06°F]) or passive cooling in a climatic chamber. Results There were no differences in exercise duration (mean difference=0.10 minutes; 95% CI –5.98 to 6.17 minutes or end exercise rectal temperature (mean difference=0.10°C [0.18°F]; 95% CI –0.05°C to 0.25°C [–0.09°F to 0.45°F] between tarp-assisted cooling (48.47 minutes [SD 8.27 minutes]; rectal temperature 39.73°C [103.51°F], SD 0.27°C [0.49°F]) and passive cooling (48.37 minutes [SD 7.10 minutes]; 39.63°C [103.33°F], SD 0.40°C [0.72°F]). Cooling time to rectal temperature 38.25°C (100.85°F) was significantly faster in tarp-assisted cooling (10.30 minutes [SD 1.33 minutes]) than passive cooling (42.78 [SD 5.87 minutes]). Cooling rates for tarp-assisted cooling and passive cooling were 0.17°C/min (0.31°F/min), SD 0.07°C/min (0.13°F/min) and 0.04°C/min (0.07°F/min), SD 0.01°C/min (0.02°F/min), respectively (mean difference=0.13°C [0.23°F]; 95% CI 0.09°C to 0.17°C [0.16°F to 0.31°F]. No sex differences were observed in tarp-assisted cooling rates (men 0.17°C/min [0.31°F/min], SD 0.07°C/min [0.13°F/min]; women 0.16°C/min [0.29°F/min], SD 0.07°C/min [0.13°F/min]; mean difference=0.02°C/min [0.04°F/min]; 95% CI –0.06°C/min to 0.10°C/min [–0.11°F/min to 0.18°F/min]). Women (0.04°C/min [0.07°F/min], SD 0.01°C/min [0.02°F/min]) had greater cooling rates than men (0.03°C/min [0.05°F/min], SD 0.01°C/min [0.02°F/min]) in passive cooling, with negligible clinical effect (mean difference=0.01°C/min [0.02°F/min]; 95% CI 0.001°C/min to 0.024°C/min [0.002°F/min to 0.04°F/min]). Body mass was moderately negatively correlated with the cooling rate in passive cooling ( r =–0.580) but not in tarp-assisted cooling ( r =–0.206). Conclusion In the absence of a stationary cooling method such as cold-water immersion, tarp-assisted cooling can serve as an alternative, field-expedient method to provide on-site cooling with a satisfactory cooling rate.