A system of capturing thermal images in a monitored location, comprising one or more motion detectors for detecting a motion in a monitored location, the one or more motion detector being a thermal motion sensor, and a thermal imaging sensor, operating in a low power mode, triggered by a motion detection indication to enter an operational mode in order to capture one or more thermal images of at least a part of the monitored location. The motion detection indication is generated by the one or more motion detectors at a detection of a motion in the monitored location.