Efectuar pagos provisionales mensuales a más tardar el día 20 de cada mes, por los ingresos obtenidos en el mes inmediato anterior;

The weather conditions varied during the test period. The coldest outdoor tem- perature was -11 °C and the warmest days were around +5 °C. Most work was carried out indoors. However, it shifted quite much between various locations and outdoors. The buildings could have big temperature differences, the warmest being the milk-room (even higher than 25 °C), while the cowshed and the fodder storage often had outdoor temperature.

Typical foot and toe skin temperature profiles are shown in Figure 15. During work in the milking parlour the foot and toe temperatures stayed relatively con- stant. When the work included tasks outdoors or in the buildings with low tem-

perature (near outdoor temperature) they fluctuated more up and down depending on the activity and environmental temperature. During the breaks the workers usually took off the footwear. That resulted in a quick rise in foot, and especially in toe temperatures. However, the return to cold brought a quick drop in tem- peratures again. One person used a warm air blower between the milking periods to dry the footwear. He was also the one with the highest mean foot skin tem- perature. -1 -2 1 2 1 -1 -1 -1 -1 -1 10 15 20 25 30 35 05:30 06:00 06:30 07:00 07:30 08:00 08:30 09:00 09:30 10:00 Time (hh:mm) Temperature (°C) -4 -3 -2 -1 0 1 2 3 4 Thermal sensation

Thermal sensation 1 Thermal sensation 2

Toe 1 Toe 2

Foot 1 Foot 2

Figure 15. Typical foot and toe temperatures during milking in a milking parlour of an- other 2 subjects. Subject 1 (a subject with lowest foot skin temperature) finished milking before 8 o’clock, entered a milk room and started other activities (feeding animals etc.). At the same time outdoor temperature started raising and contributing to the temperature raise indoors. The air temperature near the floor was of milking parlour for subject 1 around 4 °C and for subject 2 around 9 °C. Columns and numbers show the thermal sen- sation in feet (0 - subject 1; 0 - subject 2) at given time points.

On the average, the toes had 7.3 degrees lower skin temperature than the feet. The mean air temperature near the body was 12.7r4.6 °C. The mean air tem- perature in the milking parlour near the floor was generally between 5 and 10 °C, in some cases over and in few cases lower. In comparison with a field study at a harbour (Gavhed et al., 1999b) it can be said that at dairy farms the foot and toe skin temperatures stayed considerably lower. Only one person used shoes and his foot and toe skin temperatures were relatively close to these measured at the dairy farms. In another study about high-mast workers (Gavhed et al., 1999a) with lower ambient temperatures (from -0.6 to -11.5 °C), where warm boots were used, the foot and toe temperatures stayed about 1-1.5 °C higher than in farm workers. The lengths of work periods in cold in both cases were similar. Generally, the thermal sensation of the farmers was lower, too. Persons with insulated boots had

relatively less complaints on cold feet, however, they responded to wet or sweaty feet in a similar way.

There was a good relationship between low foot skin temperature and farmers response of freezing feet (questionnaire on the day). The correlation was not as good with toe temperatures. The low toe skin temperatures correlated better with the wetness sensation in feet.

The lowest mean foot skin temperature over the whole work period was

24.1r2.6 °C and lowest measured foot skin temperature was 20.1 °C (Figure 15). The same person had also the lowest measured toe temperature (12.8 °C). The subject used rubber boots with steel toe cap and one pair of thin socks. The subject rated the thermal sensation as cool (-2) at lowest. In the questionnaire the subject mentioned that the cold and wet feet were a problem.

The toe skin temperatures of all subjects dropped under 22 °C at least once. The lowest mean toe temperature over the work period was 16.0r1.4 °C (never higher than 21 °C during measurements) and belonged to another person, who used rubber boots with steel toe, 2 pairs of socks and was exposed to 10.9r6.7 °C (-6.6 to 21.4) over the whole work period. That subject had relatively high foot skin temperature (30.2r0.4 °C).

The highest mean foot skin temperature over the work period was 31.6r0.4 °C and for toes 29.1r2.5 °C (different persons). Both of them wore rubber boots with steel toe, and one pair of socks. Both of them had air temperature near body relatively high: 18.9r3.4 (outdoors -1.6r0.6 °C) and 16.6r5.0 °C respectively (outdoors around 5 °C). The first person had mean toe temperature at 21.4r0.8 °C. The second person was feeling hot all over the body during the whole day and had second highest foot skin temperature (31.5r1.0 °C).

Although, the subjects answered “no problems” in general questions, most of them pointed out problems with their footwear: cold feet (7 respondents), sweaty feet (5), wet feet (5), slip risk (3), blisters (2), not enough protection against inju- ries (2), affected work capacity (1), and bad fit, uncomfortable and affected mo- bility (1). One mentioned that the footwear becomes stiff and cold at temperatures below -5 °C. One related cold sensation to the steel toe cap.

The workers related the cold sensation in feet to the footwear material (5 sub- jects), activity change (4), contact with cold surfaces (3), the way the footwear was used (3) and sweating (3). Only one person slipped during the measuring day, but did not fall.

The weight gain of the footwear and socks was on average 27.4 g over an av- erage work period of 3.9 hours. About 6 g of that stayed in the socks. If to con- sider the weight gain to be related to sweating only, the sweat rate was 4.4r3.3 g/h per foot. However, it could not be determined how much of weight gain was due to sweating or water from outside and dirt, but also how much could evaporate.