## 4 Conclusions  
In conclusion, skin cancer is a significant global health issue, with increasing incidence rates and a substantial impact on both individuals and society. Traditional methods of diagnosis, such as visual examination and biopsy, have limitations in terms of invasiveness and detection accuracy. This has led to the exploration of alternative diagnostic tools such as infrared thermography. To facilitate research and experimentation in skin cancer diagnosis, tissue-mimicking phantoms have been utilized. These phantoms provide a controlled and reproducible environment for studying skin interactions, overcoming ethical challenges associated with human subjects. While they have limitations in replicating the complex structure and composition of human skin, physical skin models offer stability, ease of fabrication, and control over physical properties. In this research, Agarose phantoms are used. These can be easily fabricated and tailored to mimic specific skin conditions. However, they have limitations in terms of long-term stability and shelf life. This study aimed to test and compare different cooling techniques for human skin in the context of skin cancer diagnosis using dynamic infrared thermography. Six cooling methods were investigated and categorized into three types: convection cooling, conduction cooling, and evaporative cooling. The experimental setup involved an infrared camera (Optris Xi400) with microscope optics positioned 100 mm above a skin-mimicking agar phantom. The phantom was created using a 4% agar solution and had molds resembling flat skin and an ulcerating skin lesion. The measurement protocol included a cooling period of 60 s followed by a reheating process captured by the thermal camera. Data processing involved preprocessing, segmentation, and the analysis of thermal images using a Python algorithm. Based on the experiments conducted on the skin phantom, it has been observed that convective cooling methods offer a more consistent and uniform cooling effect. On the other hand, conductive methods prove effective in cooling flat objects; however, achieving uniform cooling becomes more challenging when dealing with bulging skin or ulceration skin lesions. Ice or alcohol for cooling purposes is unsuitable when used in conjunction with infrared thermography. This is primarily because the cooling effects of ice or alcohol can introduce artifacts that affect both the infrared radiation and the thermal camera's view, thereby compromising the accuracy and reliability of the results obtained. A decision matrix was used to evaluate and compare the cooling techniques based on criteria such as uniform cooling, repeatability, obstructing the view, cooling efficiency, workload per patient, patient comfort, use in a clinical setting, noise exposure, consumables and additional equipment, and price. The technique with the highest weighted score was considered the best suitablecooling method for skin cancer diagnosis. After assessing various factors, the Zimmer Cryo 6 cooler emerged as the most suitable cooling method. The Cryo 6 cooler demonstrated several advantages, including its ability to provide uniform cooling to the skin, consistent conditioning of cold air, and high cooling efficiency at \(-30\)\({}^{\circ}\)C. Importantly, it did not obstruct the field of view of the thermal camera, allowing for accurate recording of the skin lesion's cooling sequence. Additionally, the Cryo 6 cooler was user-friendly, as it did not require additional equipment or consumables, reducing the workload during clinical practice. The disadvantage of the Cryo 6 cooler is the price of the device. The application of active thermography in the identification of various types of cancers holds significant clinical importance. Ongoing research endeavors are directed toward utilizing infrared thermography for the detection of deep-seated cancers, such as breast cancer [59; 60]. Additionally, in breast cancer detection studies, skin phantoms find valuable utility [61].