[Ottriman]

Wouldn't a personal nigh immunity or complete immunity to fire be better modeled like this?

Injury Tolerance: Damage Reduction 100 (Cosmic: Can reduce injury to less then 1 +50%, Limited: Fire -60%) [270]

Then buy like 10-20 levels of temperature tolerance to be impervious to the ambient effects.

for +135 pts the Damage reduction could go up to 1000.

Edit: This build has the advantage of protecting you fully against fire with the Affects Insubstantial enhancement.