Like, I know that desert dwellers do it to protect their bodies from the sun, but isn’t that also an issue in the tropics?
I don’t actually know but maybe it has to do with high humidity favoring less clothing so your sweat helps cool you more effectively? Or perhaps the higher ease in finding shade in the tropics.
I’m no scientist but as someone from a tropical country, it has to do with humidity and covering yourself would make yourself sweat more. Also look up wet-bulb temperatures
In the tropics your problem is heat and rain. Any material in the tropics will be taking in water, and when it rains it rains so hard your eyes will hurt from all the rain rubbing against them. Thin clothes dry fast, and no clothes is twice as good. If the sun is too hot just take a siesta.
In the desert, wind is your enemy because it sprays loose matter everywhere. Hence tents and flowing clothes for protection.
If you’re farming in the tropics you want long sleeve thin clothing to limit Sun damage. Broad hats are also ideal.
I’m guessing that the fact that deserts can get very cold at night also has something to do with it. Due to high humidity, the tropics are warm around the clock, while deserts can have huge temperature variations.
From someone who lived in a place with very dry dessert like climate and moved to one that is next to the sea. It is all about humidity. In most dry climates your biggest problem is direct sun-contact. Sun will literally start to burn your skin as soon as you are out but you will be fine in a shadow. In a humid climate sun will not burn as much. But air becomes very heavy and you start to sweat non stop. So in dry climate you want a thin, preferably white clothing to prevent sun contact. While in humid climate you want as little clothing as possible.
Hovewer if you are gonna be out in sun for a long time especially in summer. You should cover your body at least your head and your body if you don’t have a sun screen. People living in forest doesn’t need to do this because they will mostly be in shadows from all the trees.
There’s definitely a functional reason based on physics for this. I find I’m hotter working out without a shirt on, that I am if I have a loose shirt or singlet on.
I’m not an expert so take this all with a grain of salt but tropics have more trees and shade. Deserts have none.
Humidity is a thing too. Deserts are dry. You sweat less. So the clothing works and keeps you cool. In the tropics id imagine it sticks to you.
I don’t think dry air makes you sweat less. It just makes the sweat evaporate faster, which also makes it more effective at keeping you cool.