How do you test the thermostat on a 2000 Chrysler Cirrus?

Any vehicle. Start it cold. Feel the upper and lower hoses as the engine warms up. If the hoses warm up the same time it's stuck open. One should get hot and the other stay colder until the engine reaches normal temp. Around 195f. Then the thermostat opens and the other will get hot. If the engine starts to over heat and one hose is still fairly cold it is stuck closed.