This paper presents a setup and measurement results for the proof-of-concept study of the feasibility of measuring flow from heating and cooling thermal response upon applying microwave heating at 900 MHz. A temperature regulated bath/pump system and microwave heating apparatus are used. With respect to various water flow rates, distinct variations in terms of the temperature rise and fall time responses (measured at a depth of about 8 mm in water) versus the flow rate, and their steady-state levels, upon applying microwave heating, are observed. This method is of particular interest in non-invasive measurement of blood perfusion using microwave heating and radiometry. Further discussions in regard to the setup improvement and perfusion estimation from the thermal response measurements are provided.