Skoda Scala Engine Overheating

That sounds very similar to an issue I had with my Scala. The engine temperature gauge was all over the place, and it definitely took longer to warm up. Have you checked for any coolant leaks around the thermostat housing or the water pump? Sometimes a small leak can also cause these symptoms.

I haven't noticed any coolant leaks. Where is the thermostat housing located? Could a faulty temperature sensor cause similar problems?

The thermostat housing is usually located where the upper radiator hose connects to the engine. As for the temperature sensor, yes, a faulty sensor could cause incorrect readings, but given your symptoms, especially the long warm-up time, it does sound more like the thermostat is stuck open. I think it's best to get it checked professionally. A defective thermostat can cause significant damage if not addressed promptly.

Thanks for the information. I took the Scala to a workshop and they confirmed the thermostat was the issue. The repair was 350€, as you said. Everything is working properly now.