An implanted heart monitor includes sensors that measure various aspects of the heart failure patient's heart. A remote heart monitoring system connects the implanted heart monitor to a care provider, such as a physician. The data provided by the implanted heart monitor permits the care provider to obtain valuable data on the heart in order to make health care decisions affecting the heart failure patient's treatment. In many cases, the measurement of core body temperature and other patient data will enable the care provider to alter the patient's treatment to address the patient's condition. The implanted heart monitor can communicate over a wireless communication link with an external monitor. The implanted heart monitor may be implemented as part of a pacing device (i.e., pace maker) or may be a separate unit devoted to monitoring functions. The external monitor communicates with a monitoring station over a communication link. The monitoring station can operate as a centralized data collection unit, collecting data from multiple external monitors and multiple implanted heart monitors. Various other aspects of a heart failure patient's heart and/or body can be monitored, such as heart rate, blood pH levels, blood CO2 levels, and any other indications of the heart failure patient's activity. Various predetermined thresholds may be set to trigger alarms and/or data reports.