A sensor and an apparatus for non-invasive measurement of an analyte concentration, the apparatus comprising: a first thermal sensor operable to determine a temperature indicative of a temperature at a location on a skin of a subject, an analyte sensor operable to generate a measurement indicative of a concentration of the analyte, a heater； a controller operable to receive a temperature signal from at least the first thermal sensor and to adjust the heater to maintain a thermal equilibrium at said location on the skin； and a processor configured to convert the measurement to a calculated analyte concentration value at a predetermined temperature.
