overheating

Hello I have a 2007 Ford mustang that won't stop overheating the coolant levels don't go down and I see no spills so I doubt it's a leak the radiator fan works and I've replaced the thermostat as well as the coolant temperature sensor to see if those where the problem but it keeps overheating what else could be the cause besides radiator or water pump as I'm going to replace those next to see if that fixes it I also live in Arizona if that has anything to do with it thanks .