2007, Piran, Slovenia

Acute and chronic heat exposure
A NEW COOLING GARMENT FOR
PATIENTS WITH MULTIPLE SCLEROSIS
Kocjan, N., Rothmaier, M.
Empa, Swiss Federal Laboratories for Materials Testing and Research
Contact person: nina.kocjan@empa.ch
INTRODUCTION
Patients with multiple sclerosis (MS) display a variety of neurological symptoms that can be
improved with increased heat loss from the body, or deteriorated with the increased heat gain.
This effect can be dramatic, with improvements in vision upon taking a cold shower or
conversely, with deterioration caused by standing near to a hot stew (Smith and McDonald
1999). In the past, patients with MS used simple, however, thermally uncomfortable
strategies, such as cold water immersion to decrease their symptoms. Nowadays, different
products, such as cooling vests, are used to achieve the same effect. However, such products
are commonly heavy, stationary and can represent an appearance barrier. Therefore, a
lightweight portable prototype cooling garment (PCG) was developed to apply functional and
aesthetical cooling for MS patients. In the present study we aimed to investigate the effect of
physical properties of the PCG on the heat loss using thermal manikins. Furthermore, we
investigated the heat loss of the PCG while mimicking everyday life conditions, such as
wearing clothing and walking.
METHODS
Prototype cooling garment: The PCG is a 3 layer laminate construction (Figure 1A). Two
outer waterproof, but water vapour permeable membranes are sealed to each other on the
edges. The thickness of one membrane (facing the air) is 15 µm and the other (facing the
skin) 25 µm. A hydrophilic fabric placed between the two membranes acts as a water
reservoir and water distributor. When a small quantity of the water is added, the hydrophilic
fabric is moistened (Figure 1B) and the evaporation through the outer membrane takes place
(Figure 1C). Consequently, due to increased heat loss from the surface on which the PCG is
placed, cooling occurs.
Hydrophilic Fabric
A B C
Figure 1 The prototype cooling garment (PCG) and its functional properties.
Measurements: For the purpose of this study, an electrically heated cylinder with the diameter
of an average upper arm and an anatomically formed manikin with body dimensions of an
average male adult were used. Both devices were run with a variable heating power (P) that
ensured a constant surface temperature of 33°C. On all occasions, the PCG was first put on
the manikin, then time was allowed for the surface temperature to stabilize, and afterwards the
water was added to the PCG. The evaporation of the water added caused an increase in P in
order to maintain the constant surface temperature of the manikin. The increased P
395