How to Fix Xbox? (only Left Side of Rings Are Red)?

I was playing some MW2 when randomly, the Xbox shuts off and the 2 red rings on the left start flashing. I try turning it off and on, but when I turned it on again, the fans went into overdrive, than stopped. So I googled this and got some info, but not a clear way to solve it.
Ok, I know that apparently, it's due to overheating. So i shut it down for say…3 hours. When I turned it on, it didn't work. Any solutions? and yes, I'd like this fixed without any money spent if possible

Suggestion:

Okay if the left 2 rings are red then you have an overheating issue.

Don't play with your 360 for a day ( let it cool) then consider investing in a cooling station. If you have been player and leaving it on 24/7 then its gonna get hot! If you think you can stop playing 24/7 then don't get a cooling station, but still let it cool for a day.

It cools by itself. But you can't use it.