Abstract: An improved probe for the measurement of the skin temperature of a living organism is provided. The probe has a probe head constructed of thermally and electrically insulative material and having a generally convex surface for skin contact. The probe head defines a depression in the surface wherein a thermocouple will lie. Additionally, provided is an apparatus using an improved first probe and an improved second probe mounted onto a housing in a mutually symmetrical relationship to measure the temperature differential of bilateral areas of the skin of a living organism.