Energy Abjuration( Complete Mage, p. 42)
Casting an abjuration spell grants you protection from energy damage.
Spell Focus (PH) (Abjuration) , Abjurer level 1,
When you cast an abjuration spell, you can choose to gain a special energy resistance equal to (1 + the spell's level) x 5. This energy resistance lasts for the duration of the abjuration spell you cast or until you are struck by any type of energy damage (acid, cold, fire, electricity, or sonic). The resistance applies to the first energy damage to which you are exposed, and thereafter you lose the energy resistance until you cast another abjuration spell.
An abjurer can select this feat as a wizard bonus feat.