A transducer for noninvasively determining an internal temperature of a location of interest in a body of a subject may be configured to receive native temperature signals originating from the location of interest without substantially receiving interfering signals. Such a transducer may include one or more shielding features for preventing interference. In addition, such a transducer may include a dielectric cavity configured or positioned to increase the native temperature signals sensed, or received, by the antenna. A transducer may be configured to multiplex signals that are indicative of a temperature of a location of interest within the body of a subject and reference temperature signals. Such a transducer may include a connector that facilitates the communication of a multiplexed signal, such as a connector for a coaxial cable. The connector of a transducer may be configured to swivel relative to an end of a cable that has been coupled thereto. Systems including such a transducer are also disclosed.