## 1 Introduction  
Diabetes mellitus (DM) is a condition affecting millions of individuals worldwide, with its global prevalence having increased rapidly over the past three decades. Diabetic foot is a common complication of DM, characterized by ulceration, infection, and/or destruction of deep tissues of the foot. This condition results from the interaction of multiple factors, primarily diabetic peripheral neuropathy and peripheral arterial disease, which impact the lower extremities of diabetic patients [1]. Diabetic peripheral neuropathy is a loss of sensory function that begins in the lower extremities. It is also characterized by pain and significant morbidity. Over time, at least 50% of individuals with diabetes develop diabetic neuropathy [2]. There are various methods to assess diabetic peripheral neuropathy. In a busy clinical environment, it is often sufficient to determine whether a patient has symptoms, particularly paintful DPN, and to assess their risk of foot ulceration using a monofilament examination. However, for evaluating early nerve damage and providing a more precise phenotyping of somatic and autonomic neuropathy, specialized screening and diagnostic tests are available, such as quantitative sensory testing, sudomotor function tests, neurophysiology, and skin punch biopsy. Current neuropathy endpoints lack sensitivity to detect early abnormalities before overt neuropathy develops, are invasive, or have repeatedly failed as surrogate endpoints of therapeutic efficacy in clinical trials for DPN [3]. Peripheral arterial disease is the lower-limb manifestation of systemic atherosclerotic disease. PAD may initially present symptoms of intermittent claudication, while chronic limb-threatening ischemia, the end stage of PAD, is characterized by rest pain and/or tissue loss. PAD is an age-related condition, present in over 10% of individuals aged \(\geq\) 65 in high-income countries [4]. Diagnosis of PAD relies on clinical assessment and diagnostic tests. The most commonly used diagnostic test is the ankle-brachial pressure index (ABPI) test, which evaluates blood flow to the limbs. However, using ABPI to assess PAD in diabetic individuals can be challenging due to medial sclerosis, the hardening of arteries. This condition can render the arteries incompressible, resulting in falsely elevated ABPI values [5]. In both cases, DPN and PAD, the diagnostic accuracy is not particularly high. Specifically, the sensitivity of the monofilament test for diagnosing DPN is 53%, with a specificity of 88% [6]. For PAD, the sensitivity of the ankle-brachial index is 35.48%, with a specificity of 97.55% [7]. Within this context, infrared thermography (IR) is currently emerging as a promising method for supporting diagnostic processes by detecting and visualizing temperature changes emitted by the body. [PERSON] [8] proposed that physiological processes and the thermal properties of the skin are influenced by various factors because the skin plays a role in regulating core body temperature. These factors change in the presence of disease, making infrared measurements useful for diagnostic purposes. Since then, numerous studies have investigated the use of thermographic imaging in diagnosing diabetes-related complications. [PERSON] et al. [9] explored the application of infrared thermal imaging technology for the early diagnosis of diabetic peripheral neuropathy. Their study identified temperature changes in plantar blood vessels associated with mild DPN, proposing a non-invasive, reliable, and early diagnostic method. They concluded that infrared thermal imaging is a dependable tool for detecting early microvascular abnormalities linked to DPN. [PERSON] et al. [10] developed a non-invasive methodology using infrared thermography and machine learning models to characterize peripheral arterial disease in patients with type 2 diabetes mellitus. Their findings indicated that infrared thermography, combined with machine learning, is a reliable tool for PAD detection in diabetic patients.