2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
The above results can be summarized as follows: (1) There are many outdoor workplaces
which are likely to exceed the reference value of ISO and TLV of ACGIH for heat stress even
late summer, as well as midsummer. (2) During indoor work in front of a furnace in metal
manufacturing and steel plants, the workers are likely to be intermittently exposed to shortterm
and extreme heat stress, which exceeds the reference values of WBGT. (3) Wearing
protective clothing together with tools during work is likely to cause additional heat stress to
the workers. (4) Despite these findings, body core temperature of the workers tends to remain
below the upper safety limit of ISO and ACGIH. This suggests body temperature is well
regulated among certain workers. (5) However, the greater body weight loss after work
suggests insufficient hydration during work. (6) Heart rate during work tended to exceed the
safety limit during work in many of the workers. (7) Many workers feel hot and
uncomfortable during work, a fact suggestive of heat strain. Some workers also demonstrated
subjective symptoms of heat disorders. Overall, these findings suggest that while many
workers in hot work environments seem well adapted to heat stress, the potential for heat
disorders is likely to exist among them.
REFERENCES
The Japan Society for Occupational Health, 2006. Occupational Exposure Limits for Heat
Stress. J. Occup. Health. 48, 302.
ACGIH, 2006. Heat stress and heat strain. 2006 TLV and BEIs. 182-199. American
Conference of Governmental Industrial Hygienists, Cincinnati.
ISO7243, 2003. Hot environments – Estimation of the heat stress on working man, based on
the WBGT index (wet bulb globe temperature), International Standard Organization,
Geneve.
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