My 1996 Mazda 626 is running hot what could it be?

many things could be wrong. coolant low or needs changing, radiator or coolant lines clogged. water pump bearings beginning to seize up. Coolant temperature sensor. here is a website that may apply to your vehicle to check the coolant temperature sensor. http://www.mazdaforum.com/archive/threads/coolant-temp-sensor-how-to-replace-pix-4746-1.html