We present further development and application examples of a thermometry approach capable of producing real-space temperature maps of operating nanoscale devices with sub-10nm resolution. The technique relies on scanning thermal microscopy with a resistive element coupled to a cantilevered tip. The resistive element acts both as integrated heater and as sensing element. A modulated temperature field is generated in the sample by exciting the device under investigation with an electrical AC bias. A map of the sample's temperature response due to different physical effects, such as Joule heating and thermoelectric effects, can be inferred from the demodulated sensor signal. As application examples, we demonstrate the investigation of thermoelectric heating/cooling at crystal phase heterostructures in InAs nanowires and Joule self-heating of individual multi-walled carbon nanotubes.