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(degrees)C [103.1(degrees)F], SD 3.1(degrees)C [5.58(degrees)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(degrees)C [48.56(degrees)F], SD 2.81(degrees)C [5.06(degrees)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(degrees)C [0.18(degrees)F]; 95% CI –0.05(degrees)C to 0.25(degrees)C [–0.09(degrees)F to 0.45(degrees)F] between tarp-assisted cooling (48.47 minutes [SD 8.27 minutes]; rectal temperature 39.73(degrees)C [103.51(degrees)F], SD 0.27(degrees)C [0.49(degrees)F]) and passive cooling (48.37 minutes [SD 7.10 minutes]; 39.63(degrees)C [103.33(degrees)F], SD 0.40(degrees)C [0.72(degrees)F]). Cooling time to rectal temperature 38.25(degrees)C (100.85(degrees)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(degrees)C/min (0.31(degrees)F/min), SD 0.07(degrees)C/min (0.13(degrees)F/min) and 0.04(degrees)C/min (0.07(degrees)F/min), SD 0.01(degrees)C/min (0.02(degrees)F/min), respectively (mean difference=0.13(degrees)C [0.23(degrees)F]; 95% CI 0.09(degrees)C to 0.17(degrees)C [0.16(degrees)F to 0.31(degrees)F]. No sex differences were observed in tarp-assisted cooling rates (men 0.17(degrees)C/min [0.31(degrees)F/min], SD 0.07(degrees)C/min [0.13(degrees)F/min]; women 0.16(degrees)C/min [0.29(degrees)F/min], SD 0.07(degrees)C/min [0.13(degrees)F/min]; mean difference=0.02(degrees)C/min [0.04(degrees)F/min]; 95% CI –0.06(degrees)C/min to 0.10(degrees)C/min [–0.11(degrees)F/min to 0.18(degrees)F/min]). Women (0.04(degrees)C/min [0.07(degrees)F/min], SD 0.01(degrees)C/min [0.02(degrees)F/min]) had greater cooling rates than men (0.03(degrees)C/min [0.05(degrees)F/min], SD 0.01(degrees)C/min [0.02(degrees)F/min]) in passive cooling, with negligible clinical effect (mean difference=0.01(degrees)C/min [0.02(degrees)F/min]; 95% CI 0.001(degrees)C/min to 0.024(degrees)C/min [0.002(degrees)F/min to 0.04(degrees)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.
