Physiological cost of work under hot dry climates in Indian industries An analysis

The possibility of using pulse rate during work as a measure of the energy coat of that work, in lieu of the more cumbersome gas analysis techniques, has been examined in actual industrial environments for varied work and thermal loads. Three sets of data from some hot dry industries situated in different parts of India were analysed : (a) extreme levels ; (b) moderate levelB ; and (c) comparatively low levels of work and heat loads. Pulse rate (PR) measurements, in conjunction with body surface area (BSA) and corrected effective temperature (CET) were found to be significantly correlated with energy expenditure (EE) at both high and moderate levels (τ = 0-889 and 0-902, respectively); the predictive ability of the corresponding regression coefficients was also high (SE of estimate—± 10%).

PR was also found to bear a linear relationship with work load at various levels of heat stress. Further, it was evident that at all levels (a), (b) and (c), the effect of work effort on observed pulse rate was more significant than that of heat exposure during work in hot environments.

From the observed relationships between PR, CET and BSA, on the one hand, and EE, on the other, it could be suggested that it is possible to predict the physiological cost of work from easily measurable parameters on the shop floor.