#5 Temperature, sensor problems
Without using software, the user may not notice high hard disk temperature also. Both CPU and newer VGA cards have protection (emergency shutdown) against high temperatures but hard disks have no such protection. Even worse, hard disks are much more sensitive to high temperatures than any other component inside the computer case. That's why most manufacturers limit the maximum operating temperature in 50-55 Celsius degrees.
Most BIOSes have support to examine the power supply voltage, fan speeds, CPU temperature etc. But it is not possible to examine hard disk temperature from BIOS. The BIOS S.M.A.R.T. function does not alert if the hard disk temperature is too high. So it is possible that the hard disk is operating in a very hot environment.
But it is important to know that many hard disk temperature sensors are not too accurate (sometimes the difference between detected and real temperature can be 8-10 Celsius degrees or even more). It is recommended to use an external device (for example an infrared thermometer) to measure the hard disk temperature and configure the difference between the measured and displayed values (calibration). So the software then displays the correct (adjusted) temperature value (if this feature is supported).
It is also recommended to examine the temperature when the hard disk is idle and when it is operating for a longer time.