I think we're on different wavelengths here. I'm talking about the scientific nature of sweating and what it does. You have stated that trapping in one's sweat would help a person stay cool. I'm saying that's the complete opposite of what would work. The primary reason behind the clothing in that channel 13 news report is to block the sun because they live in an extreme, constant beating sun, desert environment, hence:
Over thousands of years, people in the Middle East developed sub-blocking garments that allow perspiration and skin-cooling evaporation to maximize the body's natural air conditioning.
"I am cool because the material is protecting me from the heat," says Haddad. "When you take off clothes, the sun is attacking the skin."
What they had to do though, was find a material that would protect them from sun damage while also successfully wicking out the sweat and bringing it away from the body, which they've done (like Nike Dri Fit). They do not help the body re-absorb your own sweat.
It would be wise for someone to develop clothing that can help encourage evaporation despite such full coverage. That's what we've seen here. In contrast, by no means do workers wear jeans so they can trap all the sweat within their own bodies. That's just a case of them picking the lesser of two evils (sun protection/work safety vs. being hot).
Here are the basic mechanics behind perspiration: http://en.wikipedia.org/wiki/Perspiration