Which types of passenger trains in Italy have compartment windows that can be opened?

Question

What about any of the faster ones?

Answer 1

All the most modern and fastest trains in Italy have sealed windows. All the wagons are air-conditioned in summer and heated in winter, that's why windows cannot be opened by passengers.

Just on a few of the oldest trains, mostly making service just on regional routes, you can still find windows that can be opened, but nope on Intercity or Eurostar trains.

Answer 2

The older, slower ones that are not air-conditioned.

I remember being on an air-conditioned Italian train where the conductor came round and closed and locked all the windows so the air conditioning would work. Unfortunately it didn't work very well and with temperatures in the 90s outside it was a very long hot and uncomfortable journey from Rome to Brindisi...