Hey, My iMac has started to run pretty hot lately (HD runs hot, idles at around 50 degrees celsius), also the GPU diode has been around 55 - 60 degrees celsius when idle. I also hear the fans constantly, so I looked at the vents on the back of the computer and I noticed that there's a ton of dust in the back. I'm assuming this must be a problem with improper air-ventilation. But what do you guys think, should I take it to Apple and see if they will clean it some how? Also, what do you guys recommend I do to help keep it cool for the time being?