Repeated exposure to moderate cold impairs matching-to-sample performance.

To study effects of moderate cold (5 degrees C) on complex cognitive performance, subjects were exposed to cold while responding on a conditional discrimination task. The task required a correct choice of which of two simultaneously presented matrices matched a previously presented sample matrix. The effects of task performance in cold and ambient temperatures was examined on three repeated occasions, one pair of conditions per week. Responses accuracy was consistently impaired in each cold session. In addition, choice response latencies lengthened and sample response latencies decreased in all cold exposures. The data show that even moderate cold exposure that does not produce core hypothermia can impair performance of a complex cognitive task and that the magnitude of performance change is not attenuated by a brief series of cold exposures.