Experimental studies on physiological responses of clothed subjects to the variation of atomospheric humidity

Especially relation of the humidity to the sultriness

Abstract

Physiological responses to the variation of the air temperature and humidity of clothed subjects sitting in a room conditioned with an insensible air current (0.2m/sec.) were observed.
In summer, the variation of the air humidity scarcely influenced on the physiological responses, when the air temperature was below 26°C. But when it exceeded 26°C, the difference of the responses owing to the variation of humidity became evidently. At first, the electrical resistance of the skin increased markedly and then rates of pulse and respiration began to increase in the air of high humidity. The blood pressure and the rectal temperature were affected with high humidity, when the air temperature exceeded 30°C. Significant difference of thermal sensation owing to the variation of the humidity was shown in the air temperature above 26°C. And the sultrinees was felt in the range of air temperature and relative humidity over the curve on a graph which connected points corresponding to 26°C with 95 per cent, 28°C with 80 per cent and 30°C with 60 per cent. When the humidity was 35 per cent, the sultriness was not felt till the air temperature reached 36°C.
In winter, the air temperature, in which the air humidity effeted on the physiological responses was lower about 2-4°C than that in summer.