Disposable, zero-heat-flux, deep tissue temperature probes are constructed using a support assembly (500) constituted of a flexible substrate (502, 504, 506) that supports elements of the probe. One support assembly embodiment includes a folded substrate with a heater (514) and thermal sensors disposed on it. Another support assembly includes multiple sections separable into strata (542) supporting a covering guard heater (546), a central thermal sensor (508), and a thermal sensor displaced at least radially from the central thermal sensor.
