A subsystem attachable to a living being, comprising: a temperature sensor a first non-volatile memory for holding an identification information (ID) a second non-volatile memory for holding medical information an RF transceiver an LF receiver for measuring signal strength of at least one beacon signal a control unit being programmed for communicating via the RF transceiver with a readout device for exchanging the identification information and medical information in a first mode of operation and being programmed for communicating via the RF transceiver with one or more sensor devices for repeatedly receiving sensor information, and for repeatedly retrieving temperature information and signal strength information, and repeatedly transmitting said information via the RF transceiver to a central data collector in a second mode of operation.
