What happens when a temporary unit token like a spirit gets a gear like Shady Spectacles. Will it die or does it get rid of the temporary tag?

It depends on what unit Shady Spectacles copies. The copy effect overwrites the Sprite's printed traits — including its printed Temporary keyword — so if you copy a unit without printed Temporary, the Sprite loses Temporary and survives its next Beginning Phase. If you copy a unit with printed Temporary (e.g., another Sprite), it keeps Temporary and will die as normal (Rule 816.1.b).

One catch: only printed Temporary is erased. If the unit was granted Temporary by an effect (like Mirror Image or Deceiver), that granted keyword sits in a higher layer and is not overwritten by the copy — it persists and the unit still dies. Also, the Sprite remains a token regardless (tokens can't lose their token nature). (FAQ #11874; Rules 472.1.b.3, 185.1.a)