This study was carried out to see whether or not the stress induced by an academic examination raises the central temperature. A secondary object of the study was to see if examination stress might be related to the examination scores. Mean oral temperature in 108 medical students prior to examination was significantly higher than that before a laboratory demonstration. This establishes the existence of emotional hyperthermia in humans. A small but significant correlation was found between the grades obtained by the students and the difference between pre-examination and pre-demonstration temperature, higher scores being associated with larger temperature differences. However, the temperature prior to examination was practically the same in the students with the highest grades as in the students with the lowest grades. The difference between pre-examination and pre-demonstration temperature was larger in the students with the highest grades because they had a significantly lower temperature prior to the practical demonstration. On the other hand, in the lowest scoring students, temperature prior to the practical demonstration was almost as high as that prior to examination. This suggests that emotion per se does not influence the performance which apparently is related to the adequate triggering and management of the emotional response.