A zero-heat-flux temperature measurement device has first and second flexible substrate layers sandwiching a layer of thermally insulating material. A heater trace disposed on the first substrate layer defines a heater facing one side of the layer of thermally insulating material and including a central portion surrounding a first thermal sensor and a peripheral portion surrounding the central portion. A second thermal sensor is disposed on the second substrate layer facing an opposing side of the layer of thermally insulating material, and third thermal sensor is disposed on the second substrate layer facing the opposing side of the layer of thermally insulating material. The second and third thermal sensors are separated so as to provide respective skin temperatures at separate locations in a skin surface area where a tissue temperature is to be measured.
