Trainers are having such issues pretty often. I am not really liking the options where you set Health incredible high as that can cause a crash aswell. The game isn't programmed to have such enormous health amounts.
Not exactly true, I tried setting the health to 999999999999...9999999999999999999 and I didn't have any problem at all! Still, the chainsaw got me every time...
Now, IF you put your health to 0 or -1, then you can survive a chainsaw attack BUT after that you'll experience a LOT of bugs as the game has technically registered you dead (I couldn't really move much and the camera angle was locked in the position it usually goes into when you get chainsawed)
[Edited by Caboose666, 12/26/2007 2:04:46 PM]