2002 Ford Focus Overheating?

You might have air bubbles in the system or a non working radiator fan or maybe even a bad thermostat. If i were you I would not empty the reservoir cause then you'll have air bubbles for sure. Besides if the coolant system has not been worked on recently there should not be excess water in the system. You can also let your car get to normal operating temperature and see if your fan comes on. If it never comes on, there is your problem. If the car usually does fine and only overheats on occasion I guess you can keep using it and if you see it starts to overheat just put your heater on to full blast while your driving and it will make the engine temperature go down until you can safely stop and check it out. Hope this helps.