The good news is that a gradual cool down is coming. The GFS 700-mb temperature and wind analysis and forecast loop below shows the slow movement of cooler air associated with the upper-level trough presently over the Pacific Northwest into northern Utah later this week into Saturday morning.
Emphasis, however, on gradual. Temperatures will be a bit cooler than today on Thursday and Friday, but highs will still likely be in the 90s. Labor Day Weekend, however, looks quite pleasant. If you will be in Salt Lake and environs, I think you will like it.