Temporal flux is a condition in which an object fluctuates between different timeframes, jumping from past to future and vice-versa.
In 2293, the USS Enterprise-B had difficulty beaming out the passengers of the SS Lakul because they were in a state of temporal flux, caused by the proximity of the Nexus energy ribbon. (Star Trek Generations)
When the USS Enterprise-D and a Template:ShipClass became trapped in a temporal fragment in 2369, Data examined a quantum singularity lifeform disguised as a Romulan and found that his bioelectric patterns were in a state of temporal flux. This allowed him to determine that the being was not native to this space-time continuum. (TNG: "Timescape")
In an alternate timeline, Tom Paris showed a temporary temporal flux in his nervous system, after he was briefly transported back in time through a subspace fracture on Makull's homeworld in 2371. (VOY: "Time and Again")
Krenim chroniton torpedoes are able to penetrate standard deflector shields because they are in a state of temporal flux. (VOY: "Before and After", "Year of Hell")
In an alternate future, Kes' cells began to exhibit bio-temporal flux after the Doctor placed her in a bio-temporal chamber in an effort to extend her life. The bio-temporal field created by the chamber interacted with chroniton particles from her exposure to a chroniton torpedo years earlier, and caused her consciousness to begin traveling backwards through time. (VOY: "Before and After")
In 2377, Commander Chakotay was struck by a chronokinetic surge from a spatial rift. His body was thrown into temporal flux, causing him to have the liver of an 80-year-old and the kidneys of a 12-year-old. The Doctor was able to bring him back into temporal realignment with a chroniton-infused serum. (VOY: "Shattered")