Because, Like I already stated.. hot temps can cause the silicon to lose its total charge potential, thus, some charge can be lost or degraded, which cause FRAGMENTATION. That little shiny gun can be the start of a much bigger problem. Nothing happens on a computer for no reason. You must always remember that a PC doesn't do things for now reason, they operate in all numbers, everything is logical, not abstract. Everything that happens has a point behind it, even something this simple can lead to something FAR WORSE.