To protect the head the citizens in the Sahara desert wear scarves around their head. Also you need some decent insulating foot wear to prevent burning from the hot sand.
They wear lots of clothes, and no part of their body shows. But it is loosely woven, so that they stay cool.
The reason they where turbans is because the multiple layers keep your head from being sun-burned, also the excess cloth can be used as a face cover to keep you from inhaling debree in the air, the cloak keeps you warm during the cold desert nights and keeps your back from being sun-burned.
To avoid the heat people in deserts wear long flowing robes to protect their skin from the sun and to allow air to come through. The clothes are loose to prevent quick dehydration in the severely dry air. Veils protects our face and mouth to keep us living through the dangerous sandstorms. Desert people wear foot wear suitable to prevent heat and sand to coming in our feet for this may cause a severe injury
Ideally, it is preferred that you wear loose clothing but you need to make sure that it covers your entire body and not just half of it. Since the heat in intense during the day, if you don't cover your body properly there is a chance of getting a horrible sunburn. The people over there prefer thin clothing which is porous when compared to thick clothes like a sweater and joggers mainly for 2 reasons. The first being the obvious one, it's hot. The second one is that the thin clothing allows their skin to aerate in the right manner. Since their body is mostly covered at all times, it is likely that they won't get the necessary vitamins because of it and this helps them.
So if you are planning a journey to the Sahara, I would advise you to ditch clothes made of woollen or something like joggers, sarees, track pants, shorts, sweaters, sweatshirts and similar clothing items and get scarves and sunscreen so that you can stay in a good condition.
I hope this helps everyone.
As I know, it's a necessity to wear turbans there if you don't want to burn your head. I remember when I was traveling to North Africa, for some reason, I decided to take my favorite t-shirts from Printful with me, but I was wearing only special light robs because the heat there was insane, but I can tell you that the experience is awesome.