The living, breathing body is constantly sending out signals as a byproduct of its function. When a person goes to an appointment with a health care provider, it is common for a few readings to be taken - temperature, blood pressure, etc. This is information the body is generating as it goes about its business of being alive and can be a way to monitor whether it is functioning well. If the temperature is too high and/or the pulse oximetry is too low, concerns are raised.