Footwear for cold work: a field study about work on high masts

A series of field studies at cold workplaces were initiated. This paper deals with the study at a telecommunication company and the main attention is paid to the thermal responses of the feet and footwear performance. The study was carried out in February. Eight male workers were the subjects. They were selected among volunteers who carried out various jobs on high masts on four different days. The work was done in pairs on four different masts in Sweden. The insulation of the boots was between 0.33 and 0.35 m2°C/W. Various woollen socks were worn, but also cotton, fibre-pile and synthetic socks, usually together with a woollen sock. Temperature sensors were taped to the second toe and dorsal foot. The workers were observed during the whole workday. The lowest average foot skin temperature was 26.7 °C. The lowest measured foot skin temperature was 20.7 °C. The mean difference between the toe and foot skin temperatures was 7 °C. All the subjects had the toe temperatures under 18 °C at least once. The lowest mean toe skin temperature was 17.1-2.2 °C and the lowest measured toe temperature was 9.8 °C. The sweat accumulation in the footwear was at average 37 g (6-94 g) per day (7.5-3.7 g/h). Around 4 g of that stayed in the socks at the end of the day. The footwear was generally considered comfortable. Problems with the footwear were reported to be stiff in the cold, cold feet, sweaty or wet feet. One person slipped during the day, but did not fall. The footwear in combination with the chosen socks worked well in the particular weather conditions (-2 to -8 °C). However, more attention should be paid to the cold protection of toes. During low foot activity the toe temperatures dropped relatively quickly at air temperatures of about -10 °C and/or high wind speeds (about 10 m/s). (Less)