A heater apparatus is structured for use in a circuit interrupter having a thermal trip and includes a conductive device having a terminal and a heater that are co-formed with one another. The terminal includes a base and a support. The conductive device is formed from an individual metallic plate that is bent to form a number of plate elements. The base includes at least one plate element, and the heater includes at least another plate element, with the base and the heater being co-formed. A compression element is threadably receivable on the terminal and is structured to compressively retain an electrical conductor between the compression element and the base.