What happens when your motherboard fries due to heat?

My north bridge is so hot i could use it to cook dinner with, i have made this post before but now i just thought about what happens when it does kick the bucket with this extreme heat.

When the motherboard goes out will it take out the graphics card and cpu with it?

Also when i get a credit card (mainly for credit build up reasons) im going to get a crossfire board and a 4850 and crossfire it later.
Can anyone give me tips for crossfire boards? I want the cheapest crossfire mobo possible, dont see the point in getting a $250 mobo, and it needs to be Intel i plan on getting a cheap quad after nehelem.

If it's only the northbridge the northbridge is the only thing that should fry. Also temps would be useful. Killing the other parts on your mainboard usually only happens when your motherboard short circuits or a power surge or something else that does mean things to your voltages.