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.
On the road up Dethl Mountain, you will encounter the guardian, Rustus, a goron Pyro Mage. only those who can take the heat will withstand him. to defeat him, one must use a goron's worst enemy: water