It was first introduced on March the 8th of 2019 in Update 24.4 along with the said event.
Diluted Thermia is obtained by successfully closing Thermia fractures in the Orb Vallis during the event. It is obtained every time a player or their squad close 4 Thermia fractures using the same coolant canister, or by using 4 coolant canisters at once in a single fracture, which will yield one Diluted Thermia, affected by resource boosters and double-resource events but not affected by resource drop chance boosters. Said canister will then disappear, and the players will have to search for a new one if they want to continue closing fractures.
It is used to trigger the Exploiter Orb boss fight in Deck 12. Upon interacting with the console with an orange glow (next to where the Ventkids entrance would be in Fortuna), it will consume 1 Diluted Thermia and the Exploiter Orb will drop from the ceiling.
Diluted Thermia is only used from the player who triggers the fight. The other squad mates will keep their Diluted Thermia.
- Occasionally, the player may get 1 Diluted Thermia upon defeating the Exploiter Orb. There is no known condition to trigger this.