Effect of direction and rate of change of deep body and skin temperatures on performance of a rotary pursuit task.

Performance at a pursuit rotor task has been studied during the overshoot of core temperature caused by sudden cooling after heating, and the undershoot caused by sudden heating after cooling. Conditions were chosen so that effects of the absolute levels of core and skin temperature could be discounted. The results showed that the direction of change of core and skin temperature, rates of change of core temperature between -0.07 and +0.06 degrees C/min, and rates of change of skin temperature between -1.0 and +1.0 C/min did not affect performance; particular circumstances of this experiment, expecially the short duration of the changes in direction studied, make this conclusion tentative. Comparison with earlier studies indicates that the major determinants of performance at elevated body temperatures are absolute levels of mean skin temperature, with the absolute level of core temperature having a less significant role.