Wearing comfort has drawn a lot of attentions and depends on many different factors. Among these factors, thermal factor, is the most effective one. So, phase change materials, PCMs, are progressively used in order to thermal adaptability. There are chemical PCMs which are applied on textiles in different way. And in order to make this finishing permanent, these materials should have washing fastness. It has been shown that, these materials doesn´t have enough fastness on wool because of its hydrophobic nature. So, in this research, the effect of changing the wool fibre surface energy and surface charge, on performance properties of thermally adaptable wool fabrics were studied. Untreated, gaseous fluorinated, as well as Chlorine-Hercosett treated 100 % wool fabrics have been evaluated to obtain highly cross-linked PCM with acceptable fastness properties. The results indicate the necessity of having high surface energy in order to obtain appropriate adhesion and binding higher amount of solid polymer to wool fibres which results in superior thermal activity, better durability, and enhancement in felting performance. According to DSC analyzes and SEM photograph´s, fluorinated fabrics shows better results than Chlorine-Hercosett treated. Some other properties, such as air permeability, strength, washing and abrasion fastness are also investigated. Since PLA fibres which is new, has low melt temperature, they can´t be used in textile processes. In this study, the comparison of this fibre white PET has been done in order to investigate the effect of thermally adaptable properties. According to thermal analyzes, PLA fibre has higher absorbance because of having more functional groups and it can be finished in the temperature lower than it´s melt point. It also shows better activity and higher fastness than PET. Through this comparison it is demonstrated that thermal activity depends on the amount of material on fibre. In addition, using PCM in the improvement of humidity absorbance in a way that electrical resistance of these two fibres decrease using a small amount of PCM. It has been demonstrated that 3D spacer fabrics which one getting high position in textile industry, produces thermal adaptability simply using PCM. But finishing method should be done in a way that the handle and bending properties of these fabrics can be kept. In these fabrics, 3D structure acts as a carrier of the PCM. The measurement of thermal properties and investigating the thermal activity is difficult. So, an application simple method using hot plate has been presented.