Usually Transistors have a positive temperature coefficient. This means the higher the temperature the higher the resistance. And if you do your math then this will mean lower current through-put.
Thats why modern CPU's slow down as they get hot. But they do have they're limit. Early AMD's we're prone to overheating anyways. The new ones don't. They'll react the same way the Intels do when v' hot!
Just make sure you prep your system for OC'ing and don't OC in big steps.
Also watch your temperatures while your OC'ing.
And a lot of people say that you reduce the life of your system when you OC. As long as you get rid of the extra heat that's generated during OC'ing your not killing your set up.
It's the heat that reduces the life of your set up. So get rid of it the best as you can.
As for the video? Well I ask you to dismantle the cooling system on your car and do 200 miles in it and see what happens. HSF's are there for a reason.