What do you consider hot? It is normal for a car to get hot when you have an extended idle. You have less airflow over the rad at this time. Also reving the engine or brake torquing will overheat the car and possible melt the cat convertor. If the car temp is right going down the highway and only starts to climb at idle, it is normal.
Make sure you have plenty of coolant in the rad. Make sure you have no coolant leaks both of these thing cause higher than normal temps.