These are priestly domains for clerics that wanted to worship the impersonal forces of frost or fire. The elemental forces that interested in mortals, they were more like manichean forces that were constantly at war with each other. The more powerful they were, the less human-like and less sentient they were.
These are the domains that they grant to their priests. Nobody ended up playing a cleric in this campain, so I didn't end up needing to increase any above 4th level. Each domain has a religious taboo associated with it that must not be violated or the cleric loses access to the ability and spells associated with that domain until penance is made. Spells marked with an asterisk are from the Spell Compendium (3e).
Granted Power: You may breath water or water-containing liquids such as mud as easily as air. You also enjoy a +1 bonus to your caster level.
Taboo: You may not speak above a whisper.
1: Chill Touch: One touch/level deals 1d6 damage and a -1 penalty to attack rolls for 1 round. (Rule change: rather than deal 1 Str damage on a failed save, it always causes the penalty)
2: Creeping Cold*: Escalating cold damage to subject over three rounds.
3: Hypothermia*: Causes 1d6 dmg/lvl, fatigue.
4: Creeping Cold, Greater*: Escalating cold damage to subject over four rounds.
Granted Power: You enjoy cold resistance 5, or increase any existing cold resistance by 5. At tenth level this bonus increases to 10.
Taboo: You cannot cause direct harm to a creature aligned with ice.
1: Aura against Flame*: Ignores 10 fire dmg/rnd and extinguishes small fires for 1 rnd/
2: Gust of Wind: Medium creatures cannot move against wind, small are blown away.
3: Icelance*: Changes ice into lance, which attacks subject for 6d6 damage and stuns for 1d4 rounds.
4: Ice Storm: Hail deals 5d6 damage in cylinder 40' across.
Granted Power: You enjoy a +1 morale bonus to your AC and outsiders cannot attack you with melee attacks, nor control you with compulsions. Compulsions originating from non-outsiders function normally.
Taboo: You cannot cast offensive spells that have a range of touch.
1: Remove Fear: You resist -2 of morale penalty and gain +2 to saves for 10 minutes.
2: Spell Immunity, Lesser*: As spell immunity, but only 1st and 2nd level spells.
3: Corona of Cold*: Aura of cold protects you, damages others.
4: Globe of Invulnerability, Lesser: Stops 1st- through 3rd-level spell effects.
Granted Power: You enjoy a +1 morale bonus to your attack rolls.
Taboo: You must never allow a defeated foe to survive.
1: Blood Wind*: Subject uses natural weapon at range.
2: Rhino's Rush*: Your next charge deals double damage.
3: Find the Gap*: Your attacks ignore armor and natural armor. 1 rnd/lvl.
4: Fire Shield: Creatures attacking you take fire damage; you’re protected from heat or cold. You only have access to the fire version.
Granted Power: You enjoy a +2 morale bonus to your damage rolls.
Taboo: You cannot willingly sleep within a permanent structure.
1: Foundation of Stone*: Subject gains +2 AC, resists forced movement.
2: Curse of Ill Fortune*: Subject gets -3 to attacks, checks, and saves. Will sv.
3: Clutch of Orcus*: Deals 1d12 damage per round and paralyzes foe. The version of this spell that you know does fire damage.
4: Orb of Fire*: Ranged touch, 1d6/level fire damage and subject might be dazed.
Granted Power: You enjoy fire resistance 5, or increase existing fire resistance by that amount.
Taboo: You must dispose of the remains of any foe slain by your hand, via funeral pyre.
1: Burning Hands: 1d4/level fire damage (max 5d4).
2: Body of the Sun*: Your body emanates fire, dealing 1d4 fire damage/2 levels.
3: Flashburst*: Burst of light dazzles and blinds creatures in area.
4: Wall of Fire: Deals 2d4 fire damage out to 10 ft. and 1d4 out to 20 ft. Passing through wall deals 2d6 damage +1/level.