A temperature sensing system incorporates a contact temperature sensor probe for measuring the temperature of articles. The probe is able to operate effectively even in high radio frequency environments such as those present within radio frequency excited plasma processing chambers. The temperature sensing system includes a contact temperature sensor, such as a thermocouple, surrounded by a shielding sheath of a material such as aluminum which is clad with one or more layers of a cladding material. A tip insulator is provided surrounding the sheath for providing RF insulation and thermal coupling. An RF insulating and thermal insulating mounting member is connected to the tip insulator for mounting the probe on an article to be measured.