Just weighing in here with a suggestion toward comparative research: please refer to any number of historical civilizations that thrived in similar/worse conditions (deserts, etc.), and still do to this day. You’ll find that coverage is paramount — in both clothing and housing.

Non historian–

1, no sunscreen, so yeah as hot as it is, protecting yourself is better.

2, protection from brush, bugs and everything else. Yeah you want cover, even in the sun. Long distance riding a horse in shorts is a no go.

And when it isn’t summer, you don’t have much "inside " to get out of the weather hot or cold.

So yeah.