Techniques are disclosed for systems and methods using small form factor infrared imaging modules to monitor occupants in an interior compartment of a vehicle. For example, a vehicle-mounted system may include one or more infrared imaging modules, a processor, a memory, alarm sirens, and a communication module. The vehicle-mounted system may be mounted on, installed in, or otherwise integrated into a vehicle with an interior compartment. The infrared imaging modules may be configured to capture thermal images of desired portions of the interior compartments. Various thermal image processing and analytics may be performed on the captured thermal images to determine the presence and various attributes of one or more occupants. Based on the determination of the presence and various attributes, occupant detection information or control signals may be generated. Occupant detection information may be used to perform various monitoring operations, and control signals may adjust various vehicle components.