It seems that my Xbox 360 has been overheating a lot recently with the hot weather brought about by the summer season. Appropriately, I've set it up off of the desk, laid it horizontal, and placed a small (and relatively powerful) fan to blow on it at all times.

The room is small, although a bit cluttered. There is a small AC unit placed in the window and set to blow at 60 degrees throughout most of the day. However, it just keeps getting hot. I bought it new from Walmart not more than about a year ago.

Several games work on it without crashing regularly due to overheating (Dragon's Dogma, Skyrim, Call of Duty: Black Ops, Kingdoms of Amalur: Reckoning, etc.) but I've recently come into possession of other games: Prototype 2, The Witcher 2, Dead Space 2, Bioshock, and Divinity II: Ego Draconis. All of these (excluding Ego Draconis) crash not more than 10-15 minutes into gameplay.

I'm convinced it has something to do with overheating, but I've begun to have my doubts as I piece the evidence together. I've borrowed most of the above games or purchased them new or used from Gamestop. Other games work perfectly fine, but others crash regularly.

Is it time I had it repaired, or replaced? I need some strong, comprehensive answers to my problem. I'd hate to go out and spend $100 dollars to get it fixed, or even more to have it entirely replaced. Is there something more I could do that would alleviate or even fix this issue?

Additionally, I've cleared the system cache on my hard drive to re-apply updates to some of the games suffering from crashing and even installed one to my hard drive as an attempt at fixing the issue, but alas, no dice.