Systems, methods, and devices for thermal detection. A thermal detection device includes a visual sensor, a thermal sensor (e.g., a thermopile array), a controller, a user interface, a display, and a removable and rechargeable battery pack. The thermal detection device also includes a plurality of additional software and hardware modules configured to perform or execute various functions and operations of the thermal detection device. An output from the visual sensor and an output from the thermal sensor are combined by the controller or the plurality of additional modules to generate a combined image for display on the display.