Some engineering controls are taken to reduce the heat
stress of indoor workers. General ventilation is used to dilute
hot air with cooler air from the outside. Air conditioning is
a method of air cooling. Local air cooling can be effective
in reducing air temperature in specific areas. Another way
is to increase the air flow or convection using fans, etc. in
the work area. These engineering controls seem to be difficult
to apply to measures for outdoor workers. Electric fans
were put only indoors in the subjective construction site.
Thus, administrative controls are important.