Interactions and range effects in experiments on pairs of stresses: Mild heat and low-frequency noise.
Emily C. Poulton, Robert S. Edwards · Journal of Experimental Psychology · 1974
Abstract : Moderately loud noise of low frequency improves performance. When presented with mild heat, the combined effect of the 2 stresses can be smaller than the sum of the 2 separate effects. However caution is necessary in interpreting this result because performance in the control condition is affected by the pair of stresses used in the experiment.