It is running very hot, like corndog1836 says, you should give it a clean out.
If the graphics card is choked with dust it's more than likely the CPU cooler and case fans are dirty as well and should also be given some TLC at the same time.
It's best to remove the case fan/s and clean them with a cotton bud, most are marked with arrows to show you which way they are installed, but not all are, so mark them with arrows to ease reinstallation.
The graphics card is best cleaned by removing it and blowing it out using a can of compressed air (it's available in most computer stores) after cleaning the fan blades with a cotton bud-be careful, the blades can be quite fragile!
The CPU fan/cooler can be cleaned in situ just be gentle, again the fan blades can be fragile.
Use the air can outside, you'll be AMAZED how much dust it can blast out of a clogged heatsink.
Wear some sort of eye protection-even if it's normal glasses-when using the air can.
Make sure to clean BOTH sides of the CPU and graphics card fans.
If you're asthmatic be very, very careful, the dust can easily trigger an attack.