Personal comfort systems (PCSs) help enhance people's thermal comfort in cool environments and save HVAC energy consumption of buildings in winter. Current studies on PCSs (heating) were mainly conducted in artificial chambers rather than in real buildings, and heating PCSs were less tested in environments with temperatures lower than 10 degrees C. This study aims to investigate thermal comfort of residents with a traditional and special kind of traditional heating devices (Huo Xiang) as well as the corresponding heating energy in winter. Huo Xiang is widely used by residents living in the Central-South China with the cold-humid climate in winter without central heating systems. This survey included physical measurements, questionnaires, and interviews. The investigated buildings were naturally-ventilated, and their indoor temperatures ranged from 7.5 to 15 degrees C during the survey, much deviated from the comfort zone suggested by ASHRAE Standard 55. Whereas, 97.6% of residents who were using Huo Xiang accepted the cold indoor environments, and when the ambient temperature changed, they could still have neutral thermal sensations and a high level of comfort via on their own clothing adjusting, Huo Xiang power control behaviors etc. Besides, the heating power of Huo Xiang was 59.8 +/- 22.6 W per person. Further, when more residents were sharing a larger Huo Xiang simultaneously, the heating energy for each person increased. The increase of personal heating energy gradually slowed down and almost stopped when Huo Xiang's bottom area reached about 1 m(2). Moreover, Huo Xiang has the advantages of the ability to keep users comfortable, and the high energy-efficiency. These advantages make it possible to be applied in small towns and rural regions with a low economic level. (C) 2019 Elsevier B.V. All rights reserved.