Final answer:
Diez almost perished in the desert due to severe dehydration and exposure, resulting in kidney failure after being deprived of food or water for an extended period.
Step-by-step explanation:
In the text Diez in the desert, Diez almost died due to exposure and dehydration. After being stranded in the desert for six days and wandering for more than forty-eight hours without food or water, the extreme July heat led to severe health complications.
Upon rescue, it was found that one of Diez's companions had succumbed to the desert's harsh conditions, and Diez was suffering from kidney failure due to the lack of hydration and was recovering in a hospital.