Various approaches to sub-micron scale thermometry have been attempted for over a decade as researchers have attempted to push the limits of spatial and temporal measurement resolution. Among them, scanning thermal microscopy (SThM) using a microfabricated thermocouple or platinum thermistor tip seems to be the best for achieving sub-micron spatial measurement resolution in the case of solid surfaces exposed in ambient air environments.^1–6  In the case of aqueous media, however, the SThM probe has not yet been reported to be successful. Recently, one research group demonstrated the potential of SThM as a thermometry tool in an aqueous medium, but was not able to show any real temperature measurement data, which is necessary to validate the probe's accuracy and resolution capability.⁷  Another group tried to measure cellular thermal responses in a culture medium with a microthermocouple probe built on a glass micropipette, but no meaningful temperature signals were obtained.⁸