If you're using it on your lap or on top of your bed then you may be restricting the airflow through the sides of the machine causing it to overheat.
My Dell Laptop (Inspiron) is on a flat wooden table and the CPU is running at about 50°C and the disk at 31°C.
The machines cooling system may be broken and need a workshop repair. Your fan might just be clogged with dust and fluff. Some high performance "gaming" machines like Dell's XPS range have been known to suffer heat-related shutdown...
This video shows how to get to the fan on an XPS
It reveals thermal paste on the heat-sink that has gone hard making heat dissipation difficult - it should be like toothpaste.
https://www.youtube.com/watch?v=74BVvlWcbSU
Good luck...
Peccavi, January 2013
Is fan running, if not, poss new fan needed, if yes, poss air way blocked, clean out,
