Dell SXPS 16 heat problem

So, after watching videos on youtube for about 30 mins, my laptop temp. goes all the way up to 70-75 degrees and the fan noise is really loud.

I don't remember temps going up this high before.



Have you guys experienced the same thing?



And if I try and unscrew the heat sink and clean it up (since I haven't done it in about a year, although I regularly clean the fan), will that make any significant diff. to the temperature?



Otherwise, should I call Dell about this?



Any ways to fix this are greatly appreciated.



BTW, here are my specs:

OS: Ubuntu 10.10

720QM ATI 5730 w/ 9-cell

No thermal paste(kinda scared to apply it) but dust filters removed.



Thanks for the help!