I called Apple tech support about the screeching noise I started hearing more than once out of my Air. This was posted by someone else and there is a youtube video floating around also. I am going to take it to the Apple store to have them look at it, but I also asked the rep about operating temp range. He said that spikes up to 90 degrees are normal, but if it startes to climb or stay in the 90-100 range, then someone should take a look at it. Not sure how reliable this is, but thought I would mention it.