In this study, operating theatre blankets, which are one of the measures taken against the risk of the patient's body temperature drop during surgery, were examined from various angles. Textile processing method was applied using spot welding method. Within the scope of the study, the hot air vents coming out of the blankets were analysed in terms of system pressure and air outlet velocity. Instead of performing experiments on real patients, an aluminium plate assembly heated from the bottom under constant temperature conditions in the laboratory environment was used. In the second stage, values such as pressure and velocity were measured with the set-up, but heat transfer calculations could not be performed more precisely. Therefore, some calculations were performed using the ANSYS-CFX package programme. In the third stage, several different models of non-perforated blankets, which have only warm air inside and therefore cover the patient partially or completely, were compared in terms of energy consumption. Finally, different models of blankets were tested on the same plate assembly in terms of the temperature generated on the surface. It was concluded that there are clinically significant differences between forced air heated blankets and other types of blankets