well software cannot "FRY" your hardware, it can only make your processors work at 100% (which it should do anyways with no problems for an infinite amount of time) computers if designed properly can operate a 100% indefinitely, it should never reach thermal shutdown temperatures, servers operate like this all the time for YEARS.
my computer even overclocked to 4GHz and my dual gTX470s run at MAXIMUM when i play games at the highest settings, and ive played for sometimes 16hours almost straight (the computer is almost 2.5 years old now), your computer should NEVER have a problem running at MAX, its the reason why they have fans and heatsinks,
now due to the design of apple products being slim and all, they dont have nearly enough ventilation nor do they use the proper cooling methods from what ive seen
also it was a well known fact that apple ordered defective products from both ATI and nVidia and refused to acknowledge the problem until MUCH later (pretty much too late)
if you are artifact, your gpu is dead or the video ram is dead
its not blizzards fault, its Apple's fault, they should replace your video card as it is defective (and probably part of a class action lawsuit, see other threads in this forum about the MBP and MacPro defective cards)
I also got an explanation from Apple that SC2's problem is seemingly that each AND every game unit is rendered individually with no frame limiters, something that is most probably taxing the card in the same way as if you kept your own car at a constant red line speed...no graphics card is able to survive that long unless it's perfectly cooled and operated under perfect power conditions (no power surges)...
this couldn't possibly be true, most high end graphics cards take up DUAL slots, 1 for the card, 1 for the cooler, they are designed to be ran at maximum, comparing it to a car does not make sense, there are moving parts in a car, its a mechanical object. if your analogy is true than all those folding at home setups would have exploded by now, some of them have been running for YEARS at maximum with a stock cooler. im thinking in this scenario apple cheaped out on the copper heat sinks to make the computer slimer