Background
For experienced players, heating new gear can be tiresome. For example, if somebody buys new gear for Lockdown, (s)he has to run through FSC numerous times to fully level it, or ask people to donate heat by intentionally killing themselves on certain levels. It doesn't matter if the person has previously run through the clockworks 10000 times in fully heated gear, (s)he still has to run through levels again to make some new gear Level 10.
Solution: Heat Tank
Heat tanks would allow the user to store heat from previous runs and apply it to a weapon or piece of armor in the future. They would be useful to players who have fully heated gear, because the tanks would store heat that would otherwise be wasted.
Heat tanks would be purchasable from Kozma using CE. They would have a limited capacity, so each tank would only raise gear by a few levels. However, a user could have more than one heat tank, which would allow them to raise gear by additional levels if they wished.
That's silly. We already have heat amps as a CE sink.