Planes Weather Conditions and detail

Hello, Me again... Well I am really starting to dig the ATR 72-500 quite the plane and much left to learn... I can't believe this thing has operational wipers..Once I noticed this I had something pop into mind... Does anyone know if their are planes out there when icing is prevalant do the windows actually start to ice over and also prevent what visibility I guess you can have at looking at clouds (grin)..I noticed the atr 72-500 has window heaters does she do that?And if their are planes like that with that kind of detail where they at? Thanks Again,