The effect on heart rate and facial skin temperature of wearing respiratory protection at work.

Twelve New Zealand workers from a range of occupations were studied to investigate the effect of wearing air-filtering respiratory protection on heart rate (HR) and facial skin temperature (Tlip and Tcheek) whilst working. All variables were measured continuously during simulated and actual work. The former allowed physiological measurements to be undertaken during the physical activities carried out during the work task without respirators and without exposure to hazardous airborne substances. Mean heart rates in subjects moving without respirators ranged from 75 to 94 beats/min and from 77 to 98 beats/min during respirator use at work. Mean skin temperature under the mask (Tlip) increased in 11 of the 12 subjects while using respirators (range 1.2-4.8 degrees C) but Tcheek only increased in four (range 0.6-1.5 degrees C). The use of simulated work tasks in the experiment was a compromise. The heart rate data from the real and simulated work indicated that effort and workload, though not identical, were similar. The increase in skin temperature under the mask may account for the reluctance of individuals to wear respiratory protection at work. This region of the face is very thermosensitive.