Help with .DAT file

Does anybody know how to edit a .DAT file? I wanna see what the settings are because I cant find the fatigue setting anywhere in the game all i see is an option to turn it on and off.
Thanks

It doesn't matter. The fatigue slider setting is still in the settings file but the game doesn't use it. We tried it last year.

Do u know whahe fatisetting is as default? is it 50?