I have a 99 Chrysler Cirrus it runs hot in the.

Start with a cooling system flush and new coolant. The corrosion inhibitor and water pump lubricant additives wear out in about two years. Check if the electric radiator fan is turning on. Your mechanic can do a chemical check to look for signs of a leaking head gasket. Check the cooling fins on the radiator. If they're corroded and they crumble easily, they won't give up the heat to the surrounding air.