A method, system, and computer product for detecting an oral temperature for a human include capturing a thermal image for a human using a camera having a thermal image sensor, detecting a face region of the human from the thermal image, detecting a mouth region on the face region, detecting an open mouth region on the mouth region, detecting a degree of mouth openness on the detected open mouth region, determining that the degree of mouth openness meets a predetermined criterion, and detecting the oral temperature, responsive to determining that the degree of mouth openness meets the predetermined criterion.