Fan in Overdrive...

From the moment I turn my system on, the fans are blasting. (m14xr2)
When I'm idle it's the same volume, and then after around 10 minutes gaming It gets even louder, so loud that I can hear it through my headset, while gaming.
The FPS will drop from a comfortable 90 to around 10.
The only way I can fix this is to close the game or restart my computer, in some cases.
It lags out my whole computer, so that even task manager will take around 30 seconds to open.
Please help!