Here's what iStat has to say about my Mid-2007 White MacBook! All I have open is TextEdit, iCal, Preview, Safari, and Firefox. I've been noticing that my computer gets especially hot when I'm using Firefox. Should I worry about it disintegrating from the insides or are these levels of temperature perfectly normal? It's really difficult for me to keep it on my lap if I'm using it for longer than 15 minutes because the bottom of the case gets insanely hot. It's also quite discolored around the edges (sort of a greenish blue) and around where the exhaust is and it's cracked around the edges and where the hinges are around the screen.