DELL Inspiron 1525
Turning off instantly and heat faste

I am using dell inspiron 1525 and i am getting a problem of fast heating and turning of my laptop instantly at any time and while writing a DVD it get out of main memory and restarts so i am unable to write a DVD and at that time before restarting a blue scree comes telling somthin about my main memory. plz help me to get rid of these problems