My ps3 just overheated twice in the space of 20 minutes, WHYYYYY?

May be...

it has plenty of room all around and bout two metres onthe side of the fans, whats goin on?

Make sure your fan is working if it is you will feel a breeze when you put your hand in front of the ventilation duct on the fan.

or

it is that if your ps3 is close to the ground the console sucks up dust which is really really bad which can your fan to get stuck

How's the weather in your area? Is the room itself pretty cool or warm? Weather can play a role in the performance of your PS3.

Make sure the room is as cool as possible, and the fan is working.

open the window and things should be cool