If it's the Radiator is Clogged up, the Dealer can Power Flush it out with a Chemical for about $140, it's a good Flush, cleans it out and the engine nice and Bright on the inside.
Also you have a Clutch Fan. They Go Bad, in stop and go Traffic the Jeep over heats Look for a Hayden cost $50 maybe.
In the Last week My 2001 XJ's Power Steering Pump, Alternator and last year I replaced the Air Compressor and the Mechanic apparently wacked the Radiator so that went out too, all last week. I let the Dealer do the repairs. Before that I installed the Hayden Clutch fan and with every thing done driving around here in Miami the Temp does not get over 190oF on 90F days.....