I got 20 mins playing time, then I got the overheating message on screen, the fans became really loud and shortly after the system shut down automatically. I left the ps3 to cool down for about 30 mins and tried playing again, this time I got the same result after only 10-15mins playing time, system shut down again. To be sure it wasn't a fault with my system, I checked to see if it felt hot..it did not, not even slightly. I tried another game.. played for nearly 2 hours..no overheating whatsoever.
This leads me to the conclusion that LA Noire is crashing my system, fooling it into thinking it has been overheated, when infact it hasn't. Kinda blows your theory out of the water me thinks.
P.s. I applied the patch eveyone is talking about and it made no difference.
Let me tell you why I think you're wrong friend. My ps3 is relatively new (250GB Slim Model PAL), I've never had an overheating issue. My system sits in the middle of the floor, with nothing else around it to make it hot. I play fifa 11 in 10 hour stints sometimes and my system has NEVER overheated. This all changed when I played LA Noire.