An Apparatus and method are provided for sensing temperature of a sample. Apparatus 2 has a sensor 5, positionable relative to a sample 3, which is responsive to temperature of a region of the sample at each position of the sensor. Sensor circuitry 10 provides a response signal indicative of the sensor response at the position of the sensor. Sample-temperature controller 12 controls temperature of sample 3 independently of sensor 5. Sample-temperature controller 12 effects a time-dependent modulation of the sample temperature such that a time-dependent heat flux is generated between the sample and the sensor at the position of the sensor. Temperature analyzer 11 extracts time-averaged and time-dependent components of the response signal due to the modulation of the sample temperature, and processes the components to produce an output indicative of temperature of the sample at the position of the sensor.