Heating technology is highly important to the traditional view, as the need for the heating of the body and the space has always been among the main concerns of humanity to survive. Yet, in situ observation of heating systems in historical buildings for diagnostic and monitoring purposes of old technologies and for their maintenance and preservation is troublesome necessitating thorough analysis. There are few studies conducted on especially Roman and Turkish baths in Anatolia, but not much on other building types. Hence, investigation of development and use of different building systems applied in historic buildings being the key concern, in this manuscript the thirteenth to the seventeenth century Anatolian Seljuk and Ottoman period hospitals (daruşşifas) have been selected as case studies, which were the core places for the treatment of patients. Those historic hospitals were profoundly evaluated to lighten the issue by means of literature and historic survey, archival research, field observationd and comparative analysis. Most of the heating systems and complementary elements detected in those buildings have not been able to function at present due to inappropriate intervantions, lack of maintenance, deterioration caused by passing of time, and change in life practices. Thus, determination of heating systems in historical hospitals with this study seemed to be useful not only for the assessment of those functional systems but also for the understanding of thier technological development, in order to raise the issues of their conservation and to determine their conservation measures.