A common mistake when writing adventures set in deserts is to assume that the climate is too ferociously hot to wear armor. Historically, most battles in deserts involved troops dressed in protective armor. Although they would have been miserable during the hottest part of the day or the hottest part of the year, desert weather isn't intolerably hot 24/7.
A legend tells of a people living deep in the desert, they appear at first as ordinary human beings, sometimes impersonating someone familiar to the PCs, before causing their features to disappear, leaving a blank, smooth sheet of skin where their face should be.
King Addas loves charades, and has a troupe of mimes in his harem. To ensure that they can never cheat he has had their tongues cut out, which is why they always look so miserable and never open their mouths (the stump of a tongue is not a pleasant sight).