Efficacy of wrist/palm warming as an EVA countermeasure to maintain finger comfort in cold conditions
Koscheyev, V.S.; Leon, G.R.; Treviño, R.C.; Koscheyev, V.S.
Aviation Space and Environmental Medicine 72(8): 713-719
2001
ISSN/ISBN: 0095-6562 PMID: 11506232 Document Number: 526697
Introduction: This study explored the effectiveness of local wrist/palm warming as a potential countermeasure for providing finger comfort during extended duration EVA. Methods: There were six subjects (five males and one female) who were evaluated in a liquid cooling/warming garment (LCWG) wearing modified liquid cooling/warming (LCW) gloves in three different experimental conditions: Condition 1: Stage 1 - no LCWG, LCW glove inlet water temperature 33degreeC; Stage 2 - no LCWG, LCW glove inlet water temperature cooled to 8degreeC; Stage 3 - no LCWG, LCW glove inlet water temperature warmed to 45degreeC; Condition 2: Stage 1 - LCWG and LCW glove inlet water temperature 33degreeC; Stage 2 - LCWG inlet temperature cooled to 31degreeC, LCW gloves, 8degreeC; Stage 3 -LCWG inlet water temperature remains at 31degreeC, LCW glove inlet water temperature warmed to 45degreeC; Condition 3: Stage 1 - LCWG and LCW gloves 33degreeC; Stage 2 - LCWG inlet water temperature cooled to 28degreeC, LCW gloves, 8degreeC; Stage 3 - LCWG remains at 28degreeC, LCW glove water temperature warmed to 45degreeC. Results: Wrist/palm area warming showed a statistically significant increase in finger temperature (Tfing) in Stage 3 compared with Stage 2. Blood perfusion showed a trend toward a significantly greater value in Stage 3 compared with Stage 2. The LCW gloves were significantly more effective in increasing Stage 3 Tfing in Condition 1 (33degreeC) compared with Condition 3 (28degreeC). Across conditions, subjective perception of heat in the hands was significantly greater at Stage 3 than Stage 2; perception of overall body heat showed a trend for higher heat ratings in Stage 3 than Stage 2. Conclusions: Local wrist/palm warming was effective in increasing blood circulation to the distal upper extremities, suggesting the potential usefulness of this technique for enhancing astronaut comfort during EVA while decreasing power requirements.