This is still sometimes done. The newest section of the Freie Universität Berlin campus (the “Holzlaube”) was built so that the inside remains comfortable with

This is still sometimes done. The newest section of the Freie Universität Berlin campus (the “Holzlaube”) was built so that the inside remains comfortable with no A/C and minimal heating. Thick walls, as you said. I don’t know how applicable architectural cleverness will be in densely populated cities in the developing world that are threatened by global warming. That seems like an impossible situation.