The impact of the room temperature on the occupants' recollection of watched video program was studied in three different thermal conditions, i.e., warm condition (29°C), neutral condition (25°C), and cool condition (22°C). After watching 30 minutes video program, the subjects answered the questionnaire, which asked the contents of the program. This test was repeated one month after the video watching and three months after it. It was found that there was no significant difference in the percentage of correct answer even in the rather difficult questions of the above questionnaire between neutral and warm condition. Since arousal sensation for the neutral condition voted by the subjects was close to that for the warm condition, the percentage of selecting the choice of “I do not remember the contents” in the neutral condition might be similar to that in the warm condition. The CO₂ production from the occupants was calculated by using the CO₂ concentration and the ventilation rate for each thermal condition. The significant differences in the CO₂ production per one occupant among three conditions were not detected. The shallow breathing caused by worse air quality was not observed clearly.