There is a difference in the temperature read by a Telemetry transmitter dependent on where the device is surgically implanted. Transmitters implanted Subcutaneously (SQ) will measure a lower body temperature then transmitters implanted Intraperitoneal (IP). IP placement positions the transmitter body in the abdomen exposing it to a more realistic core body temperature.
This graph below provide an example of to transmitters placed in the same animal, one IP and one SQ. This demonstrated what the potential difference could be based on transmitter placement.