Boosted Fortitude (3.5e Feat)
From D&D Wiki
 Boosted Fortitude [Psychic, Save]
Benefit: Regardless of character class, you have a base Fortitude save equal to half your overall character level (rounded down), or +1 on your existing Fortitude save if this is better. Thus, a single-classed fighter will get +1, while a rogue or wizard will usually get half his/her level. Normal modifiers apply, including +2 for Great Fortitude and +1 for Psychic Healing.