Is it ok to let Mac air run 24 full hours? I have a MacBook Air (11-inch, 2011) ,I am now downloading iTuneU courses 24 hours.There is only one app iTunes running,is it ok?
Yes of course. I had my MacBook running for a week once. And as long as you don't do any heavy tasks, such as rendering or video compression, you won't have any overheating issues.