OBJECTIVETo probe the tendency of physiological and psychological change of armored vehicle drivers working continuously in hot environment.

METHODSTen cross-designed standard subjects were divided into control group and driver group. The driver group worked continuously in 32 degrees C approximately 38 degrees C and RH 50% approximately 80% environment. Heart rate, body temperature, systolic blood pressure and pulse pressure were synchronously and dynamically determined during work. Psychological parameters such as profile of mood states (POMS) questionnaire, serial addition/subtraction (SAS) and two-digit search (TDS) selected from neurobehavioral evaluation system (NES) before and after work were also tested.

RESULTSThe curves of the four main physiological parameters rapidly synchro-rose to a peak at (36 +/- 3) min, whereafter the curves descended smoothly. At (144 +/- 8) min, the curves climbed up to the second peak. The determination of the behavioral psychology revealed that the degree of fatigue of the drivers increased gradually when the working time prolonged, and the grip descended by great extent, excitement reduced markedly after work, but the negative mood, such as confusion and depression were increased, error of visual apperceive-operation was increased, right decreased, intelligence reduced, rapidity and delicacy of movement reduced.

CONCLUSIONThe physiological parameters of armored vehicle drivers working continuously in the hot condition appeared double-peak effect, the 1st peak was at (36 +/- 3) min, and the body was in mobilizing stage. Whereafter, the body was in smooth stage. And at (144 +/- 8) min, when the 2nd peak appeared, the body then was in physiological tolerance limit stage.