A hard disk drive (HDD) capable of controlling its own internal temperature during testing. A test program embedded in the HDD is run only within a pre-determined optimal test temperature range. The internal temperature of the HDD is kept within this pre-determined test temperature range by switching HDD operation modes back and forth between a higher heat generating Rapid Seek Mode and a lower heat generating IDLE mode. The HDD is thus kept within the optimal test temperature range without the use of external heating and/or cooling devices.