The torrid zone was the name given by ancient Greek and Roman geographers to the equatorial area of the Earth, so hot that it was impenetrable. That notion became a deterrent for European explorers until the 15th century.
Aristotle posited that the western half of the temperate zone on the other side of the world from Greece might be habitable and that, because of symmetry, there must be in the Southern Hemisphere a temperate zone corresponding to that in the northern. He thought, however, that the excessive heat in the torrid zone would prevent the exploration.[1]
Strabo referred to:
In 8 AD the poet Ovid wrote in his Metamorphoses.
Pomponius Mela, the first Roman geographer, asserted that the Earth had two habitable zones, a north and a south one. The second population were known as Antichthones. However, it would be impossible to get into contact with each other because of the unbearable heat at the equator (De orbis situ 1.4).
Many Europeans had assumed that Cape Bojador, in Western Sahara, marked the beginning of the impenetrable torrid zone until 1434, when the Portuguese sailed past the cape and reported that no torrid zone existed.[2]