Numerous threads on here go on about the heat of their Macs and how the fans run at 6,000rpm and 'is this normal?' and 'How can I change the fan speed?' etc. Why is this an issue? Surely Apple design a computer to do what it does and react accordingly as heat builds-up. Surely a Mac isn't going to allow itself to get so hot the chips melt themselves off the board. So what do you all worry about it so much?