Reported on discord multiple times.

Found a bug: when I sleep through the night and the iron my bloomery finishes cooking due to the time jump, the blooms get stuck at brilliant white until I forge them into ingots.

Perhaps this is a hint for a fix: I just fired up the bloomery again, and slept through the night causing it to instantly be done. Now, the blooms are brilliant white and seem to work fine, no instant cooling
Actually, the blooms are not cooling at all
Throwing them into water also instantly cooled them

By the sound of the reports it seems sleeping / ICalendarTickable skipping is giving blooms an invalid heat value?