Extreme warmth and sensorimotor coordination

¹ Medical Research Council, Applied Psychology Research Unit, Cambridge, England

Six subjects were exposed for 30 minutes on three occasions at 48-hour intervals to a very warm, humid climate with a wet bulb temperature of 105°F (41°C). During the second and third exposures the subjects worked continuously to keep a pointer aligned with a target mark, as it moved erratically from side to side. Accuracy of alignment was normal at first, but deteriorated rapidly and progressively. Movement of the pointer was greater than usual right from the start and changed little thereafter. Rectal temperature rose steadily during the exposures. Failures to correct progressively greater misalignments of the pointer were thought to indicate a growing inattentiveness to the task and a general deterioration in the organization of performance.