Liquid Ice fails to cool the skin surface as effectively as crushed ice in a wet towel.

Physiotherapy Theory and Practice 26(6):393 (2010) PMID 20658925

One sought to compare surface cooling produced by two cryotherapy modalities (crushed ice in a room temperature wet towel and Liquid Ice). Twenty-five university students (10 female and 15 male) between 19 and 29 years of age (mean+/-SD: 21.36+/-2.33) participated in this study. Skin surface temperature was measured prior to, immediately after 20-minute application, and 20-minute postapplication of the cryotherapy modality using an infrared camera. Both cryotherapy modalities decreased the baseline skin surface temperature (crushed ice: 28.6+/-1.3 to 6.8+/-1.8 degrees C; Liquid Ice: 28.6+/-1.6 to 25.2+/-1.56 degrees C; p<0.001). Similarly, at 20 minutes postapplication of both cryotherapy modalities the skin surface temperature remained significantly inferior to baseline (crushed ice: 21.8+/-1.0 degrees C; Liquid Ice: 27.4+/-1.6 degrees C; p<0.001). The magnitude of the decrease was greater after the application of crushed ice in a room temperature wet towel than Liquid Ice, both immediately after application (temperature fall: 21.8+/-1.6 degrees C versus 3.4+/-0.7 degrees C; p<0.001) and 20 minutes postapplication (temperature fall: 6.8+/-0.8 degrees C versus 1.2+/-0.6 degrees C; p<0.001). Assuming that greater cooling seems to be better, the present results suggest that: 1) a 20-minute application of crushed ice in a room temperature wet towel is more effective at cooling skin temperature than evaporative cooling menthol-based products and 2) Liquid Ice(TM) is not a clinically useful modality.

DOI: 10.3109/09593980903229240