A compact resistive thermal sensor is provided for an integrated circuit (IC), wherein different sensor components are placed on different layers of the IC. This allows the lateral area needed for the sensor resistance wire on any particular IC layer to be selectively reduced. In a useful embodiment, a plurality of first linear conductive members are positioned in a first IC layer, in spaced-apart parallel relationship with one another. A plurality of second linear conductive members are similarly positioned in a second IC layer in spaced-apart parallel relationship with one another, and in orthogonal relationship with the first linear members or in parallel with existing wiring channels of the second IC layer. Conductive elements respectively connect the first linear members into a first conductive path, and the second linear members into a second conductive path. A third conductive element extending between the first and second layers connects the first and second conductive paths into a single continuous conductive path, wherein the path has a resistance that varies with temperature. A device responsive to an electric current sent through the continuous path determines temperature of the path from the path resistance. Two or more of the thermal sensors could be connected in series, for use in measuring critical IC circuits.