Macbook Pro won't go to/stay asleep.

So I've noticed that whenever I close my Macbook Pro to put it to sleep, I'll come back hours later and the fan will be running full speed and every inch of it is extremely hot to the touch.

And just now I noticed that even when I put it to sleep manually from the menu and close it, I'll come back with the same issue. When I open it again the fan suddenly stops and then starts back up again when it kicks back to life.

Any ideas?

Try resetting the SMC as that controls the sleep - wake and power functions.

Just tried it. Nothing changed.

It really seems like closing it wakes it up. Like if I put it to sleep with the menu and then close it it wakes up again...

If your MBP is still under warranty or extended Apple care, make an appointment with your local Apple store genius bar and take it on in for them to look at. If the SMC reset didn't work there may be a hardware problem with the logic board that only Apple can diagnose properly.