RATIONALE: Here, we investigated the effectiveness of the FLIR T560 thermal imaging camera in detecting hypothermic changes associated with radiculopathy caused by spinal stenosis. This study aimed to determine whether the FLIR T560 could serve as a portable, efficient tool for diagnosing radiculopathy and its related sympathetic dysfunction in clinical practice. PATIENT CONCERNS: A 77-year-old male had a 1-year history of neuropathic pain in the right distal lower leg, confirmed as L5 and S1 radiculopathy due to central stenosis at L4-5 and L5-S1, as shown by MRI and electrodiagnostic studies. The FLIR T560 recorded thermal images in an insulated room, revealing a significantly lower surface temperature (approximately 1.0°C difference) on the lateral and posterior right distal lower leg and right toes compared with the left side. By referencing the color map and scale, we estimated that the relative temperature difference between corresponding areas was approximately 1.0°C. DIAGNOSES: L5 and S1 radiculopathy due to central stenosis at L4-5 and L5-S1. INTERVENTIONS: A transforaminal epidural steroid injection targeting the right L5 and S1 nerve roots was conducted. OUTCOMES: The patient's pain improved significantly. LESSONS: The FLIR T560 camera offers a portable and convenient alternative to traditional digital infrared thermographic imaging, allowing real-time thermal imaging in a clinical setting without the need for additional equipment. Our case report suggests that the FLIR T560 is a valuable tool for detecting sympathetic dysfunction associated with radiculopathy. Further studies with larger patient populations are recommended to validate its clinical utility.