IF the problem is temp related & your console is overheating, that's a problem you must take care of as the priority anyway.
It could also be that the kernel panics & the console shuts down.
That could be caused by a number of things such as (but not limited to):
1. Hdd failure (try another hdd)
2. Hdd errors (scan disk for error in recovery mode)
3. Mounted game issue, whether it's ISO or legacy JB folder format, dump from disc again using a different tool & a different storage device for destination.
You might also try mounting it from an external USB drive, big iso files will need to be stored on a ntfs partition.
It's better to mount your games from USB storage anyway, it means less work/stress for your internal hdd when you play a mounted a game.
I have changed 3 hard drives till now.
Now , my fat PS3 is acting wiered , when I turn on console it first glow yellow and blinking red light with 3 beeps....I'm afraid it is the YLOD !!!!
Please guide me....