The authors have focused on a thermal difference between office rooms and break rooms and have proposed an integrated thermal control method to improve workers’ intellectual concentration. In addition, they conducted experiments to objectively and quantitatively investigate its effectiveness. In the control method, the office room is set to be cool environment while the brake room is set to be warmer because it is expected to improve the quality of break time when taking a rest in the break room and to encourage their quick switchover to restart working when returning to the office room. Two experiments were conducted in summer and winter in this study. In each experiment, the intellectual concentrations were compared under two environments, which were (1) the integrated thermal control environment as a proposed condition and (2) no thermal difference environment between office room and break room as a control condition. Cognitive tasks were given to the participants under both conditions and their response time were measured and CTRs (Concentration Time Ratio) were calculated. As a result, in summer, participants’ concentration was improved in the proposed condition, while in winter, there was no difference between two conditions.