Sliding glass windows in an open space: plain or treated glass?
Having an opening in your walkway to the exterior (we call that a “breezeway” where I live in the U.S.) only affects the solar heat build up if there is a breeze. Without a breeze to purge the air, the room will heat up and become uncomfortable. 

Where you live, I’d definitely use tinted solar glass (like Solar Bronze double pane thermal glass.) If you use any type tinted solar glass, it should be double pane, because the glass is “coated” with the special treatment and could be scratched off if left exposed on one side. 

Also, remember to have the glass made of “safety glass” (tempered or laminated) if it’s close to the floor or close to a door. (Here in U.S. it has to be safety glass if it’s within 18” of floor, 12” of a doorway, plus other special conditions.) I’d check with your local building department for current requirements.