However, suppose immediatly afterwards the person goes right
back out and repeats the same actions (walking around outside
without a coat in -60 weather, for example) that caused them
to have the flu in the first place.
They get it again, only this time it's worse.

Akane in BE didn't do anything to caused her disorder.

She failed to seek treatment.

Inability to seek treatment voluntarily is part of the disease.  In
traditional abuse scenarios, the abuser sought voluntary treatment less
than 1% of the time.  This would be magnified in the IED scenario.

Yes, I did some homework on this before I wrote it.  ^_^

-Richard