2007, Piran, Slovenia

Personal protective equipment
HEAT AND WATER VAPOUR TRANSFER FROM WET UNDERWEAR
IN THE PROTECTIVE CLOTHING SYSTEM UNDER SOLAR
RADIATION
Takako Fukazawa*, Emiel A. den Hartog, Yutaka Tochihara, George Havenith, and
TERMPROTECT Network
TNO Defence, Safety and Security, Department of Human Performance, Soesterberg, The
Netherlands, * Presently with Fukuoka Women’s University, Fukuoka, Japan
Contact person: fuka@fwu.ac.jp
INTRODUCTION
Protective clothing (PC) protects the body from harsh hot and cold environments. However, it
also produces physiological problems, such as an additional load and heat stress due to its
heavy weight, restricted evaporation of sweat, and a decrease in agility due to its stiffness. In
the present study, the heat and water vapour transfer, relevant to risks such as heat stress and
steam burn during exposure to a high radiation (solar), have been described through the
modelling of test results.
METHODS
The experiment has been performed under a condition of 20°C and 40% RH. An experimental
set-up, shown in Figure 1, is composed with a simulated skin model, underwear, an air gap of
8 mm thick, and a single PC layer, to simulate a practical PC condition. The underwear was
totally moistened with distilled water, simulating heavy sweating due to a heavy workload. In
the experiment, the model was exposed to a radiation source of about 700 W·m -2 with a
laminar air-flow of 1 m·sec -1 . One underwear and three types of the PCs were selected for the
study. The PCs have almost identical properties except the colour. The properties of the
materials use are summarised in Table 1.
Figure 1. Experimental set-up (left) to simulate the practical protective clothing
system and its picture (right).
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