Go into the BIOS and check for fan settings there, also look for a "Hardware Monitor" entry and check the fan there. If you change any settings be sure to hit "Save and Exit", then it will restart.
From Windows - Grab HWINFO here and install it to monitor the fans. You can also watch the CPU voltage and temps (see image) and let us know how it's going.
If that doesn't work, need some details:
1 - age & model for motherboard, RAM & PSU?
2 - recent hardware changes?
3 - recent environment changes (I.e., moved to Mongolia by yak, etc)?
4 - recent software changes?
5 - any error codes / beep codes?