The application of heating film to hands reduces the decline in manual dexterity performance associated with cold exposure

• Published in: European journal of applied physiology Vol. 124; no. 10; pp. 3095 - 3103
• Main Authors: Wang, Gang, Fan, Junli, Yue, Ting, Gao, Xinpeng, Zhang, Tingran, Hurr, Chansol
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2024; Springer Nature B.V
• Subjects: Adult; Biomedical and Life Sciences; Biomedicine; Cognitive ability; Cold Temperature; Cross-Over Studies; Doppler effect; Female; Fingers - blood supply; Fingers - physiology; Hand - physiology; Heating - instrumentation; Heating - methods; Hot Temperature; Human Physiology; Humans; Male; Motor ability; Motor Skills - physiology; Motor task performance; Occupational Medicine/Industrial Medicine; Original Article; Psychomotor Performance - physiology; Skin Temperature - physiology; Sports Medicine; Temperature requirements; Young Adult; Finger temperature; Grooved pegboard test; Manual dexterity; Cold exposure; Hand heating
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-024-05482-7

Purpose
Exposure to cold temperatures decreases finger temperature (T
fing
) and dexterity. Decreased manual function and dexterity can be serious safety risks, especially in tasks that require fine motor movements that must be performed outdoors. The aim of this study was to determine whether hand heating with a minimal power requirement (14.8 W) results in a smaller reduction in T
fing
and manual dexterity performance during mild cold exposure compared to a non-heated control condition.
Methods
In a randomized crossover design, twenty-two healthy participants were exposed to a moderately cold environment (5  ºC) for 90 min. One condition had no intervention (CON), while the other had the palmar and dorsal hands heated (HEAT) by using electric heating films. T
fing
and cutaneous vascular conductance (CVC) were continuously monitored using laser Doppler flowmetry. Manual dexterity performance and cognitive function were assessed by the Grooved Pegboard Test (GPT) and Stroop Color-Word (SCW) test, respectively, during the baseline period and every 30 min during the cold exposure.
Results
After the cold exposure, T
fing
was higher in HEAT relative to CON (CON 9.8 vs. HEAT 13.7 ºC, p < 0.0001). GPT placing time, as an index of dexterity performance, was also shorter in HEAT by 14.5% (CON 69.10 ± 13.08 vs. HEAT 59.06 ± 7.99 s, p < 0.0001). There was no difference in CVC between the two conditions during the cold exposure (p > 0.05 for all). Cognitive function was similar between two conditions (p > 0.05 for all).
Conclusion
The proposed hand heating method offers a practical means of heating fingers to maintain dexterity throughout prolonged cold exposure.