This thesis presents the thermal evaluation of the first prototypes of ParoDüse, a flexible bipolar cold atmospheric plasma (CAP) nozzle, developed through an iterative design and testing process. The final application envisioned is the treatment of periodontitis, which requires the nozzle to come in direct contact with oral mucosa. Therefore, thermal safety requirements set the general aim of the optimization process: temperature of both nozzle and effluent shall remain below 41°C. Across three successive design generations, key geometric parameters—including inter-electrode distance, gas channel width, and the position and shape of the gas outlet—were systematically modified to investigate their influence on the nozzle’s thermal behavior during operation.