To begin sealing Thermia Fractures, players must acquire a Coolant Canister. These can be found by defeating any Coolant Raknoid which usually follows the Exploiter Orb around, and the Exploiter Orb herself can be found patrolling around the Temple of Profit in Orb Vallis.
After the Coolant Canister is acquired, the players must then look for Thermia Fractures, which are scattered across the Vallis and can be easily identified from afar as a fissure constantly erupting with orange thermia.
Sealing can be initiated by "interacting" the fracture with a Coolant Canister, which will in turn initiate a Mobile Defense-like objective where players defend the canister from attacking Corpus troops. Sealing a fracture takes 3 minutes to complete, though instead of showing the time the UI will display a counter up to 100. Each fracture closed will award 1 point to the player's overall score, and a quarter of the normally blue canister will turn orange. Closing 4 fractures with the same Coolant Canister, or closing 1 fracture with 4 Coolant Canisters will award 1 unit of Diluted Thermia and an additional 3 points, for a total of 7 points. The Corpus aren't the only threat to the players however, as the fracture has a chance of generating a "Burp", which occurs every 5-15 seconds and further increases the difficulty of defending the canister.
Players can speed up acquiring Diluted Thermia and points by feeding up to three additional Coolant Canisters within the first 30 seconds of sealing the fracture. Each canister consumed increases the sealing process by 50 seconds (or an additional 25 units to the counter, up to 175 units/5.5 minutes if four canisters are used). Adding additional canisters also increases the initial Alert level during the sealing process and increases the frequency of burps, as well as introducing special burps for added difficulty. Below is a list of potential Burps and their effects;
|Level Burp||Increases the current Enemy Alert Level.||Only appears with at least 2 canisters.|
|Eximus Burp||Spawns additional Eximus units.|
|Nullifier Burp||Briefly spawns a Nullifier bubble around the fracture.|
|Radiation Burp||A sudden yet brief burst of Radiation damage, with a guaranteed proc.||Only appears with at least 3 canisters.|
Increases the damage output of nearby enemies.
|Only appears with at least 3 canisters.|
|Raknoid Burp||Spawns Thermic Raknoids, which resemble Mite Raknoids and deal Heat damage with their attacks, but are otherwise identical behavior-wise.||Only appears with at least 2 canisters.|
Note that it is also possible to mix canisters with differing levels of Thermia. For example, two canisters can be inserted into one fracture to create one half-full canister, and then used on another fracture with an empty canister to yield a full canister of Diluted Thermia and 7 points.
The number of fractures sealed in post-mission summary is the total number of fractures sealed across the event, rather than the number sealed during an individual session.
The points that players gather from sealing fractures accumulate across multiple instances of Thermia Fractures, which means that any points that the players had accumulated in one instance of Thermia Fractures will be carried over to future instances. Below is a list of rewards and the minimum number of points required to get them. The player can only obtain these rewards once.
- 5 Points: Operation Buried Debts Emblem
- 25 Points: Amalgam Shotgun Spazz and Amalgam Serration
- 50 Points: Amalgam Barrel Diffusion and Amalgam Organ Shatter
- 75 Points: Operation Buried Debts Sigil
- 100 Points: Opticor Vandal (Includes weapon slot and pre-installed Orokin Catalyst)
Lastly, the Diluted Thermia collected from fractures can be used to summon and fight the Exploiter Orb by interacting with the Thermic Condenser located at the far end of Deck 12. Note that the Exploiter Orb can be summoned whether or not an instance of Thermia Fractures is active, and is only limited by the amount of Diluted Thermia the player has on hand.