Energy Immunity

Warlock Invocation
Level: Dark, 8th
Components: V, S
Casting Time: 1 standard action
Range: Self
Duration: 24 hours
Saving Throw: None
Spell Resistance: No

You gain immunity to acid, cold, electricity, fire, or sonic damage for 24 hours. Choose the energy type when you use the invocation. If you use this invocation again while the first duration is still active, the new immunity replaces the old one.

(Complete Arcane, Page 134)