2007, Piran, Slovenia

Table 1: Environmental conditions outdoors and in the thermal chamber
°C
40
35
30
25
20
15
10
5
0
0
10
Occupational Thermal Problems
Outdoors Indoors
Air temperature, ta(ºC) 23 23
Mean radiant temperature, tr(ºC) 33 23
Air velocity, v(ms -1 ) 0.75 0.73
Relative humidity, ø(%) 54 52
Solar radiation(Wm -2 ) 423
20
30
Min
40
50
Outdoor ta(ºC)
Outdoor tr(ºC)
Indoor ta(ºC)
Indoor tr(ºC)
Outdoor v(m/s)
Indoor v(m/s)
Figure 1: Environmental conditions outdoors and in the thermal chamber
The weights of the subject before and after the exposure and calculated sweat production are
presented in Table 2.
Table 2: Weight of subject and clothing and sweat production.(g)
60
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
m/s
Outdoors Indoors
Before After Before After
Semi-nude Weight 91037 90406 88538 88145
Clothed Weight 91780 91207 89188 88818
Weight of clothing 743 801 650 673
Sweat
production(g/h)
557 310
It can be concluded that the subject produced 247g/h of additional sweat due to the
contribution of the sun. This can be interpreted as adding a thermal load of 80 Wm -2 to the
body.
STUDY TWO: Estimation of the contribution of the sun to thermal stress using a thermal
manikin: The thermal manikin was suspended near to the subject during the experiment
carried out indoors and outdoors (STUDY 1) and hence under identical conditions. The heat
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