Overheating problem '97 TJ

I was idling in traffic on the 4th waiting to get into parking at the new
Heinz Field in Pittsburgh for fireworks and all of a sudden my temp jumped
up to just below the red and the 'check gauges' light came on. I did a
quick u=turn and got into a non-congested lane and got moving to get some
air flowing and it calmed down to a little over 210, but just a hair higher
than usual. I was running the a/c on max since i had the top on still.
Shortly after it cooled back down to a more reasonable level I noticed
another strange problem....when I came to a stop the oil pressure would dive
down to zero and the light would come on again. Once it cooled down for
good after parking for awhile this went away too. It's done it a few more
times since and it's usually during slow driving with the a/c on. The oil
level seems fine and it's Valvoline full synthetic 10w30. Coolant is topped
off and is a nice green color, not nasty stuff.

Any theories for this happening?

Shawn