The first phase changes the raw material through microbial activity. Temperature is one sign of that activity, but a high peak does not describe the condition of the whole mass. Record several positions and interpret the pattern with moisture, structure, additions and turning or aeration events. Keep sensor location on the same chart as the reading.
Compare what happened before a change. Did the batch become compacted? Was a different lot introduced? Did aeration stop? Was water added unevenly? These questions help decide what evidence is missing before an operator changes the process. Follow the established method for the system; an outdoor heap and an aerated bunker should not be forced into one identical calendar.