Apparatus (100) for use in sensing temperature in a wellbore, comprising: tubing (110) comprising a plurality of temperature sensor modules (120, 320, 420, 520, 620, 720) provided at locations along the inside of the tubing, said temperature sensor modules comprising temperature sensors (321, 421) provided at least in part by at least one semiconductor element having electrical properties that vary with temperature; an electrical network (115) configured to electrically connect to the semiconductor elements to in use allow measuring of the respective electrical properties of the semiconductor elements to infer a thermal characteristic of the semiconductor element; and at least one control module (130, 330, 430) electrically connected to multiple temperature sensor modules, via the electrical network, and configured to receive and process an electrical signal associated with the temperature sensor modules to enable inference of the temperature of the semiconductor elements and the environment to which the tubing is exposed at the location of that semiconductor element.