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Abstract
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Working conditions for fire fighters can be
described according to the environment temperature and the incident radiant heat
flux. Measurements for this study in buildings for fire fighting training have
shown that fire fighters are typically exposed to radiant heat fluxes of between
5 and 10 kWm(-2) during this kind of exercise. The heat load can nevertheless be
much higher. In one case, 42 kWm(-2) was measured. The temperatures reached
between 100 and 190 degrees C at 1 m above ground, going up to 278 degrees C in
one case. Human trials have been performed with 17 fire fighters. After
exercises (about 15 min) in a heated room, the mean core temperature of the fire
fighters rose by 0.6 degrees C with a surrounding temperature of 31 degrees C
and 1.0 degrees C with 38 degrees C. The sweat production varied from 0.7 to 2.1
lh(-1); 16% to 45% of sweat remained in the clothing layers. During the
exercises in the training buildings, a mean of 48 degrees C has been measured
between fire fighters' clothing and workwear. These conditions lead to an
increase of the relative humidity in all the jackets up to 100%. When the fire
fighters came out of the fire, the humidity remained at this level in the PVC
coated jackets while it was in some cases strongly reduced in breathable
jackets. |