Some of the users of SpeedIt reported a bug related to the readout of the temperature, we have been tested the digital readout and we discovered that the problem is related to a bug in the microprocessor.
This bug could be affect your MacBook is Speedit temperature readout is below 30ºC, and dont' change. If your temperature vary from 20 up to 80 don't worry you are not affected by this bug.
The bug is documented by Intel and happend only in some processors and is the following:
AE18 Processor Digital Thermal Sensor (DTS) Readout stops updating upon returning from C3/C4 state. (Source Intel Corp.)
If this is your case, we recomend to go to Apple to verify your computer, because in case of thermal problems the processor will never get protected. You can solve this issue too with the last firmware from Apple, Intel propose a solution via bios or efi.
Source