Jeep Repair: jeep overheating, cherokee sport, operation temp

Question
We have an 01 Cherokee sport, 4.0 L., V6, automatic transmission that recently started overheating.  More coolant was added as it was low.  It overheats when put into gear and returns to normal temp. when in park.  What could be causing the problem?

Answer
can you please re-write your question in a way that i can understand what you are telling me. thanks

"It overheats when put into gear and returns to normal temp. when in park."

are you telling me that you can sit there with your foot on the brake peddle and keep the truck in park, but if you put it in gear with your foot stillon the brake it will raise the temp?

plus what is the temp at right now? 210 is normal operation temp. for a jeep of that year.