2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
Johnson and Park (1981), the exercise-mediated Δ Tc,th predicted by Equation 1 is 0.26,
which is reasonably close to the values observed by Johnson and Park, 1981 and by Kellogg,
et al. (1991).
462
NORMALIZED CVC
160
140
120
100
80
60
40
20
0
26 28 30 32 34 36 38 40
MEAN SKIN TEMPERATURE: C
Figure 2. Normalized cutaneous vascular conductance and forearm blood flow plotted as
functions of mean skin temperature. Open symbols identify experimental data and filled
symbols designate computed values. Data were obtained from the following sources:
Circles, squares, and triangles from Stephens, et al (2001), and + from Charkoudian, et al.
(1999a). The filled circles were computed.
The reflex effect of T s on cutaneous vasoconstriction is defined by ) T CVCM( s . Two fairly
recent studies (Charkoudian, et al., 1999b; Stephens, et al., 2001) provided the data
necessary to define CVCM. Those data are plotted in Fig. 2.
Locally mediated cutaneous vasoconstriction defined by CVCL(Ts) is strong when
Ts < 34 o C and decreases markedly above 34 o C. Shown in Figure 3 are local vascular
conductances derived from forearm blood flows (FBF) reported by Wenger et al. (1986).
Conductances were normalized by dividing the measured FBFs for each subject by his FBF
at Ts = 35 o C. Also shown are conductances reported by Charkoudian et al. (1999a, 1999b),
again normalized to a value of unity at Ts = 35 o C. CVCL is represented by the solid line in
Fig. 3.