Heat

Overview
Whenever a Templar takes an action (such as attacking, buffing, moving) his/her Leviathan battle suit generates Heat. Every turn, this heat is reduced by an amount dependent on several factors. If a templar's heat surpasses their maximum heat threshold (typically 100 points of heat), they begin to suffer damage every turn. The templar maximum heat threshold may be increased by certain equipment and buffs which will allow a templar to safely operate at a higher temperature. If a Templar reaches or surpasses 256% of their base Heat (including modifiers) their suit will suffer a critical shutdown and his or her AP and MP are both set to 0 until the temperature drops below 256% Heat.

Overheating Damage and Willpower
When a Templar's suit exceeds their maximum heat threshold (usually 100) he or she will suffer 1d12 damage at the end of their turn. If the suit exceeds double the threshold, he or she will suffer 1d16 damage at the end of their turn.

This damage is reduced by a roll from the templar's Willpower. If a Templar were to have 6 Willpower, have 140 Heat, and an unmodified heat threshold of 100, he or she would take 1d12 - 1d6 damage (but never dealing negative damage) at the end of his or her turn, unless the heat is removed by an Engineer's skill.

Heat Reduction
The Leviathan armor suit dissipates thermal energy via heat sinks. The heat sinks will continuously vent heat out of and away from the battle suit. The efficiency of these heat sinks is dependent on difficulty:
 * Easy: Burn off 18 Heat per turn
 * Normal: Burn off 16 Heat per turn
 * Demanding: Burn off 15 Heat per turn
 * Hard: Burn off 14 Heat per turn
 * Brutal: Burn off 13 Heat per turn
 * Nightmare: Burn off 12 Heat per turn
 * Ironman: Burn off 10 Heat per turn

Heat reduction is more significantly reduced by inactivity. Unused MP grants heat reduction at the end of the turn. MP gained via buffs and special gear will not contribute to this extra reduction. The efficiency of heat vents while stationary is also difficulty dependent: ''e.g Scout (6MP) on easy with +3MP from Overdrive, has moved 3 squares. Assuming no other actions are taken that turn the Scout will burn 30 heat: 18(base) + (4 x 3 (unused core MP)). The bonus MP are used last when moving, hence 42 heat burn off requires complete inactivity.''
 * Easy & Normal: Burn off 4 Heat per MP
 * Demanding, Hard, & Brutal: Burn off 3 Heat per MP
 * Nightmare & Ironman: Burn off 2 Heat per MP

Talents that reduce Heat or increase Max Heat

 * Engineer's talent Heat Sink reduces heat from a single target. Can be cast multiple times per turn on the same templar.
 * Engineer's talent Manual Vent reduces heat from a group of templars and lowers their MP by 3, further reducing heat over time.
 * Neptune's talent Full-Vent reduces heat from the Neptune him/herself and lowers MP by 2, further reducing heat over time.
 * Hydra's talent Redline Reactor increases the maximum heat capacity and fire damage of the templar for 4 turns. This delays the penalties, so as to give the templar time to cool down.

Talents, Armor and Gear that lower MP
Whenever a Templar wears armor, equips gear or is affected by a buff that causes a loss to MP, he or she gains an advantage in burning off heat. This is because those lost MP are unavailable for movement, but are still available for heat reduction. Furthermore, these hidden MP are counted twice for reducing heat.

Example: Playing on Hard difficulty with a Templar wearing armor that reduces MP by 1 (in exchange for defensive capabilities) that sits idle (or even maintains an Overwatch panel from a previous turn) for a single turn would burn: 14 (baseline) + 5 * 3 (MP unspent) + 1 * 3 * 2 (hidden MP unspent) = 35 Heat.

Talents lowering MP

 * Engineer's Fortify Position reduces MP by 1-2 depending on talent level.
 * Flame-Tank Engineer's Manual Vent reduces MP by 3.
 * Scout's Field of Focus reduces MP by 1-4 depending on talent level.
 * Neptune's Full-Vent reduces MP by 2.
 * Paladin's War Machine reduces MP by 1-2 depending on talent level.
 * Berserker's Battle-Lock reduces MP by 2-3 depending on talent level.

Armor lowering MP
Infantry Armor (Soldier, Engineer)
 * Density-Plated Leviathan: -2MP

Heavy Armor (Soldier, Captain, Berserker)
 * Heavy Leviathan: -1MP
 * Slayer-Core [RELIC] : -2MP
 * Mammoth Leviathan: -1MP
 * Warstar Leviathan: -1MP

Neptune Armor (Neptune):
 * Sentry Plate: -2MP

Hydra Armor (Hydra):
 * Vigilant Plating: -2MP
 * Mag-Core Leviathan: -1MP

Gear lowering MP
Armor Coatings (Hydra, Neptune, Paladin):
 * Goliath Plating: -1MP
 * Goliath Retrofit: -1MP
 * Titan Sheathe: -2MP

Armor or Gear that alters Max Heat
The alternative to improving heat dissipation through loss of movement is to alter the maximum capacity through Armor and the defensive Gear option(s) available to a class. This will increase the thresholds for 100%, 200% & 256% heat, thereby reducing the odds of taking higher level heat damage or an enforced shutdown.

Example:

Hydra with Bi-Plate Heat-Regulation (+30 Max Heat), Kinetic Refine-X (+30 Max Heat) and Shadowflame Armor (+16 Max Heat) will not suffer standard (d12) heat damage unless they accrue 177 heat, with 353 heat required to suffer enhanced (d16) heat damage, and must reach 450 heat to force a shutdown.

Armor altering Max Heat capacity
Assault Armor (Berserker, Paladin):
 * Cavalry Assault : +40
 * Giltwing Assault : +20

Hydra Armor (Hydra):
 * Shadowflame Armor: +16
 * Heavy Void Armor: +30

Flame Tank Armor (Engineer, Hydra):
 * Descendant Flame-Tank [RELIC]: +35

Neptune Armor (Neptune):
 * Obliterator Legion [RELIC]: +16

Gear altering max Heat capacity
Pilot Suits (Scout, Captain):
 * Blitz Kit: -10

Targeting Systems (Soldier, Berserker):
 * Fortified Backbone: +15

Leviathan Reactors (Hydra, Engineer):
 * Hydraul-Injector: +15
 * Vent Manifold: +15
 * Reinforced Reclaimers: +15
 * Boosted Reactor: +10
 * Cyclone Reactor [RELIC]: +60
 * Kinetic Refine-X: +30
 * Rerouted Reclamation: -15
 * Heat Rewiring: +30

Sensorkit-Mods (Engineer, Scout):
 * Typhoon Scanner [RELIC]: +0 heat for using Sensorkit Scan talent.

Armor Coatings (Hydra, Neptune, Paladin):
 * Thermal Enclosure: +20
 * Bi-Plate Heat-Regulation: +30
 * Volcanic Shielding: +15

Expert-Procs (Berserker):
 * Roavin Detonator [RELIC]: +30

From the above list it should be noted that between equipment and talents Hydra's have the most options for raising their heat limit to extreme levels (max +120 gear, +150 talent), with Engineer's (max +95 gear), Neptune's (max +46 gear) and Berserker's (max +45 gear) coming in 2nd, 3rd and 4th respectively. Arguably, the worst class for heat management is the Scout, having no items that reduce movement or increase heat capacity.