Overheating of xbox360 slim.

7 hours is a lot of time! I would take a break from playing your Xbox 360 for 1-4 hours. And then,if that won't work, have Microsoft repair it!

It is a special power board adapter that disables the electricity current and it clicks off the power to the devices connected and prevents electricity overload to your devices, which can be damaging to electronic devices.

What is a surge protector and I think it may have been a power outage

If it is shutting down within a few minutes at a time it could be an electrical fault. Is it still in warranty? If it is the repair should be free, if not it might cost you to repair it. How long have you had the console? Do you still have a store receipt
on where you purchased it? If you to send it to Microsoft it can depend on location but an estimate could be 2 to 3 weeks or it could be a months wait depending on where you live in the world.

Give it an hour or two break if it is running hot the last thing you wanna do is keep turning it on. You are only going to make things worse constantly turning it on. When it has cooled down move it to somewhere else preferably a well ventilated area and
turn it on. Also be sure to check the side vent to see if it isn't clogged with dust or dirt or anything foreign. If it is still overheating send it in for repair.