No the sensor belt does not need to be worn to record the core temperature from an ingestible core pill sensor or skin temperature from the wireless dermal patch. However, the SEM does need to be connected to the sensor belt to be able to receive the signal, the sensor belt acts as an antennae. If not being worn the sensor belt with connected SEM must be placed within the transmission distance of the core pill (1 meter) or dermal patch 1.75Meters. Obviously, if the sensor belt is not being worn by the subject the other physiological parameters recorded by the equivital LifeMonitor will not be monitored.