How to replace thermostat on 200 kia sephia

So long as the meter does not go into the Red/Orange zone, then it is likely just getting hotter because of the hot weather.

You can help avoid any problems by not driving in stop and go traffic and trying to park the car in shady spots when you can. Not driving for more than an hour helps and driving with the Vent on will help too (but it will make it extra hot inside the car, lol).

If it reaches the red zone, then park it and get ready, cause it's time to replace the thermostat and do a general tune up.

Follow the upper radiator hose back to the motor.
Remove the clamp and disconnect the hose.
There should be two bolts holding the thermostat housing to the engine.
Remove the two bolts and pull the thermostat housing from the engine.
remove the thermostat
clean off the old gasket
replace new thermostat and a new gasket
Bolt the thermostat housing back to the engine.
Put the radiator hose back on, and refill the radiator.
All the above method I learned from automotix.net/autorepair/askquestions.html