Finger skin cooling on contact with cold materials: a comparison between male and female responses during short-term exposures

Abstract

This study compares male and female contact cooling responses in order to ascertain whether a particular sex is at a greater risk to cold injury. Ten volunteers (five male, five female) participated, touching blocks of four different materials (aluminium, stainless steel, nylon and mahogany wood) with finger contact forces of 1.0 N, 2.9 N and 9.8 N, at a range of surface temperatures (−35°C to +5°C) appropriate for the thermal properties of the material. Contact temperature (T _C) of the finger-pad was measured over time using a T-type thermocouple. Under fast cooling conditions (below 10 s to reach T _C=0.5°C), no significant difference was found between the cooling responses of males and females (P>0.05) for the 12 conditions tested. Under slow cooling conditions (above 10 s to reach T _C=0.5°C), females were found to have significantly faster skin cooling than males (P<0.05) for 18 of the 24 conditions tested. In order to investigate whether differences in hand anthropometry between these representative groups of males and females were related to differences in contact cooling response under slow-cooling conditions, a general linear model approach was used. Subsequent analyses of the residual variance in contact cooling data after the effects of material type, finger contact force and surface temperature had been accounted for showed that both sex and hand size correlated significantly with contact cooling response (P≤0.001) with hand size showing the stronger impact and possibly being the determining factor. Conclusive proof of the latter would require an additional experiment using males and females of equal hand dimensions instead of representative groups as used here. This study showed females to be at a higher risk during contact with cold objects.