ps3 cooling unit

[diamondfoxxx]

My ps3 broke down on me (worked flawlessly for about 5 months)--the movie I was watching played fine until about 20min into the movie it freezes and then a message pops up saying 'invalid disc'; after that I tried another movie and the same thing happened. Only this time seconds into the movie it stopped and came up with 'invalid disc'.
So I took it back to the store I bought it from and they said I should have kept it in an air-conditioned room or used the 'cooling unit' (I live in Sri Lanka, and it's quite hot). And, I can't do the things you guys do by calling Sony normally when your ps3 breaks down because that service is unavailable here.
So what they do is they send it to Singapore to have it made. So I gave mine to them for repair.
The question is, should I buy this cooling unit once my ps3 comes back repaired? I heard it was not good for your ps3?
Help would really be appreciated.