Thermal measurement systems are critical to industrial manufacturing, environment monitoring, medical care and research. But their trustworthiness requires proper calibration and traceability. This review explores the latest calibration techniques for widely used thermal measurement instruments, such as thermocouples, resistance temperature detectors (RTDs), thermistors, radiation thermometers and thermal cameras [1-4]. The research offers a practical approach to assess instrument performance using statistical quality control methods such as repeatability, stability and measurement deviation [5,6]. Moreover, it discusses the measurement uncertainty evaluation process using the internationally recognized Guide to the Expression of Uncertainty in Measurement (GUM) approach, enabling laboratories to enhance their measurement confidence [7]. The study also compares the main calibration techniques, including fixed-point calibration, comparison calibration and electrical simulation [8-10]. Fixed-point calibration is the most accurate method and can achieve uncertainties of 0.5 mK for standard platinum resistance thermometers (SPRTs) at the triple point of water [11,12]. In contrast, comparison calibration is more adaptable, and is the method commonly used in industrial practice for its convenience and ease of operation [13,14]. As an example, a Type K thermocouple was calibrated using an SPRT as the reference standard [15]. The measurements found expanded uncertainties (coverage factor k = 2) of 0.08 °C at 0°C and 1.2°C at 1100°C, demonstrating the uncertainty growth at higher temperature [16]. Evaluation of uncertainty via Monte Carlo simulation (10⁶ iterations) also verified the uncertainty model and the accuracy of the results [17,18]. Finally, the review offers recommendations for setting calibration intervals, establishing uncertainty budgets and participating in proficiency testing schemes [19-21]. These benchmarks are particularly helpful for laboratories accredited to ISO/IEC 17025, where technical proficiency and traceability of measurement are required [22,23].