They already have that immunity.
Dark Elf
Increases Experience gain in Dual Wield Skill Line by 15%, reduces damage taken from Lava by 50% → No changes
Dynamic: 6% Max Stamina and Magicka → Increases your Max Stamina and Magicka by 1250.
Resist Flame: 3% Max Magicka and 2079 Flame Resistance → Increases your Max Health by 600 and your Flame Resistance by 2310. You are immune to the Burning status effect.
Destructive Ancestry: 7% Flame damage and 2% Frost/Shock Damage → Ruination: Increases your Weapon and Spell Damage by 258.