Such a character would:
- add 6 to resist heat-based non-Malediction Afflictions;
- add 3 to resist heat-based Malediction and otherwise DR-ignoring Afflictions;
- subtract 3 from heat-based Innate Attacks;
- add 3 to resist effects that are somehow defined as heat-based or have a heat Power Source, even if they're neither Afflictions nor IAs, but for some reason come with a Resistance roll (e.g. Magic magic, Realm magic and RPM spells).