This study aims to improve user comfort and satisfaction regarding the thermal environment in the open plan office, which is a current challenge in the workplace and limited research addresses it. The main difficulty in an open plan setting is that changing the room temperature in an area affects all occupants seated nearby. This issue in addition to individual differences in perceiving the thermal environment create a great challenge to satisfy all occupants in the workplace. This study investigates the application of an advanced thermal system that allows individual control over their immediate thermal environment without affecting the thermal environment and comfort of other occupants. A prototype of an office chair equipped with thermal control over the seat and the back was produced and examined in an open plan office in November 2014 in Leeds, UK. Forty five individuals used the chair in their everyday context of work and a survey questionnaire was applied to record their views of the thermal environment before and after using the chair. The results of the field study revealed 20% higher comfort and 35% higher satisfaction level, due to the use of thermal chair. Thermal measurements showed acceptable thermal conditions according to the ASHRAE Standard 55-2013. The thermal performance of the chair further analysed through Computational Fluid Dynamics (CFD) illustrating the thermal distribution around a sitting manikin. It predicted an improvement in the local thermal comfort of the user. The results indicated that user thermal comfort can be enhanced by improving the local thermal comfort of the occupant. Further research is recommended to improve the design and application of the thermal chair to improve user thermal comfort, also the accuracy of the thermal predictions using CFD analysis can be improved.