An electrode for applying electric fields to a patient includes a plurality of ceramic elements (e.g., ceramic discs) that are designed to be positioned against the patient's skin. Electrical connections are made to the ceramic elements (e.g., using a flex circuit). Temperature sensors (e.g., thermistors) are preferably provided at at least some of the ceramic elements to sense the temperature at the skin beneath the ceramic elements, so that appropriate action can be taken if an overtemperature condition is detected.