You have 2 options.
1: take the laptop apart and clean the fan.
2: Undervolt the CPU.
I would suggest you do both.
Follow these guides to disassemble the systemHow to take apart HP Pavilion dv6000 laptopHow to disassemble HP Pavilion dv6500, dv6600, dv6700, dv6800 notebooks
Blow the fan out with canned air, vacuum, etc.
Remove the heatsink. Clean off the TIM or Thermal pads, whichever is on.
Apply new TIM to the CPU and reseat the heatsink.
If you have Thermal pads you'll have to find new ones *shudder* or buy some copper shims
There are quite a few on eBay for HP *6***.
Put everything back together. If you have any spare screws,well... might wanna take it apart again
Now to undervolt the CPU. Undervolting drastically lowers the temps without incurring any performance hit. These are my results: Pentium M
and a Pentium T4300
Instead of following the guide on here which is overly complicated and out of date, I'll show you an easier way.
1: Run HWmonitor and Orthos small FFT's test.
2: Let Orthos run for 10-15 mins. Take a screenshot and save it (for posterity and to post in the undervolting thread)
) Exit Orthos and HWMonitor. Let the system sit idle for a few min to let it cool down.
4: Open Throttlestop and lower your voltage as far as it will go, Then click the Turn on button.
5: Verify in CPU-Z that the voltage you set in ThrottleStop is in effect.
6: Run Orthos, if the voltage is to low it should throw error within 5 seconds.
7: If Orthos gives an error, bring the voltage up a notch in ThrottleStop and run Orthos again.
8: Once you have a found a voltage that doesn't give errors, run Orthos for 10-15 mins. No errors? GRATZ! You have successfully undervolted your CPU
9: Save the ThrottleStop setting and set it to start with windows.
10: Post before and after screeny's here: Laptop Undervolting Thread
Hope this helpsEdited by emc_2 - 2/14/11 at 2:05pm