Err over heating problem

Okay, well first off, the car stays at the right temp most of the time. Sometimes when just sitting there idling, the tempe gauge decides to mosy its way to the big "H" so... I have to get the rpms up to around 2000 and hold it there, and then it goes back down. Its like I have to give the fan more power to cool the thing down. I'm nto sure why.. Its not like it idles to low, it idles at 6-700

Check your coolant level. You probaly need to top it off.

Contrary to popular belief a cars cooling system IS NOT a sealed system, over time coolent will evaporate from it. I recomend checking/ toping off the thing every 4 to 6 months.