Abstract: The specification discloses a temperature/gas probe for use in a steel-making blast furnace comprising two tubes pivoted together at one end and having mounting means at their free ends adapted to co-operate with support structures within the walls of the furnace, the pivot means and the support means being such that the probe in use adopts a shallow V-configuration substantially corresponding to the profile of the burden in the furnace. Each tube supports a plurality of thermocouples which extend from the tube in spaced relation along the length of the tube. The thermocouples are housed in tubes within the tubes, said thermocouple housing tubes extending to the free ends of the probe tubes to facilitate easy replacement of the thermocouples as they wear out. The thermocouples are connected to a recording apparatus which provides a temperature profile print-out at any desired time. The thermocouple housing tubes may also be used to collect gas samples from the furnace.