There is provided a method, a device and a system for modifying at least one parameter used by a video processing algorithm, such as a motion detection algorithm, an object detection algorithm, or an object tracking algorithm, for monitoring of a scene (102). The method comprises: receiving a first (105a) and a second (105b) video sequence of the scene (102), wherein the first video sequence (105a) is captured using a thermal camera (104a) such that the first video sequence (105a) comprises thermal information being indicative of temperatures in the scene (102), and applying the video processing algorithm to the second video sequence (105b), wherein at least one parameter used by the video processing algorithm is modified based on the thermal information comprised in the first video sequence (105a).