Most armors have the misc option "Asbestos Lining," which adds some Energy resist (not fire, because Bethesduh) and "prevents you from being set on fire." Except it doesn't. In no case, with no version of it, at any time, have I not been set on fire by Molotovs, the Burning effect from "wave"-capacitor Laser weapons, etc. It doesn't seem to matter what body part you apply it to, either: the player's engulfed in flames, they take periodic damage hits, etc.