With your description of its environment, you should have no problem whatsoever. Overheating can often occur on older laptops, but rarely on desktops. And if you have Win 7 running, it implies a recent machine. I don't have my Win 7 system fired up at the moment, but quite honestly, you need not worry about that. Here's a useful web site for more info though:
http://www.howtogeek....anage-power-settings/
Personally, I don't like Win 7, I'm a firm believer in the old adage 'if it ain't broke, don't fix it'. I know that there are many new features in Win 7 over XP, but to change things like the Control Panel format was just stupid. Then we have to contend with Win 8 soon.... Sigh...