Introduction: The fundamental principle of traditional medicine is grounded in the Cold–Heat concept, wherein cold weather can pose Cold–Heat imbalances, causing joint pain, muscle pain, and Bell’s palsy. Acupoint thermometry, which involves measuring dermal temperature at specific acupoints, is a valuable method for evaluating these imbalances. However, conventional infrared thermometers, measuring body radiation for diagnostic and therapeutic purposes, cannot record temperature changes over time, which can impede the treatment of Cold–Heat imbalances according to traditional medicine protocols. Methodology: This study aims to develop and validate a novel infrared thermometer (ATHERM) that accurately measures dermal temperature at three critical acupoints, namely bilateral GB-20 and GV-16, against two widely used commercial thermometers (the infrared MICROLIFE FR1MF1 thermometer and the FLIR C5 camera), on 50 healthy individuals, over three repetitions. Results: The obtained results showed no statistically significant differences between ATHERM and commercial thermometers at the three acupoints in healthy individuals (p > 0.05). Such outcomes were consistent across three repetitions, indicating excellent accuracy and reliability. Discussion and conclusion: The study findings provide strong scientific evidence for the accuracy and reliability of ATHERM in measuring acupoint temperatures, which suggests its promising applications as an effective tool for diagnosing and treating Cold–Heat imbalances in traditional medicine, as well as providing useful temperature data for the health science sector.