I fixed this in my campaign by making the amount of hit points increase as one's base Fortitude save increases. I got the idea from the Dragon's Toughness and Dwarf's Toughness feats from Masters of the Wild. What do you think?
Toughness [General]
You are tougher than normal.
Benefit: You gain +3 hit points. The number of bonus hit points granted by this feat increases to +6 when your base Fortitude save bonus reaches +5, and increases again to +12 when your base Fortitude save bonus reaches +11.
Special: A character may gain this feat multiple times. Its effects stack.
[Edit: And no, I am not thread hijacking. This feat change was made intentionally so that it would be a viable option in a game with a feat every level, so this post at least does pertain to the thread topic

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