high engine heat

ok, my engine temp. is being weird. when im driving the temp. seems to be fine. its whenever im at a stop where the temp. rises sky high. i check all my hoses and they seem to be connected. also everytime i fill up the reservoir it goes empty pretty quick. i was thinking about changing the thermostat but i have no idea how to do it. can someone show me a picture of where the thermostat is located. thank you

Turn on engine and let it heat up. check the top radiator hose when the engine is hot. If it is cool, then you need a new thermostat. If it is hot, then your thermostat is fine. What car is this? Did you inspect the radiator for cracks? Check everywhere, and anything that has coolant.