Only the northern and southern poles of this world are inhabitable by humanoid races. In the coolest winter, the lowest planetary temperature would still be over 90 degrees Fahrenheit and in the hottest part of the summer the lowest temperature still exceeds 115 degrees Fahrenheit. The temperature added to the scarceness of water and the devastating sandstorms prevents humanoid life from existing very long on the surface. For these reasons, there are no humanoid settlements on this world.
The surface might be void of humanoid and other life that would be recognizable to humans, however life does still thrive on this world. Creatures from the elemental, para-elemental and quasi-elemental planes can thrive here, well those from the hot ones. There are also some rather unique creatures that are indigenous to the world, creatures that have evolved over time to take the heat at various latitudes. Many of these beings only emerge at night, hiding deep in the sand or in deep holes or cracks in rocks during the day
Below the surface however is teaming with life. Elemental and non-elemental creatures fight for control of areas of the underdark with humanoid explorers caught in the middle. Several wizards and priest have attempted to control the chaos of Froltoil's underdark with little success, most of the creatures here seem to have a natural resistance to control of any kind. Plus, sense humanoids are removed from the equation, the priest powers are diminished with out worshipers to his/her god.
Many of the creatures here are bug-like in appearance, which is why sages call this the "bug world". But not all are, there are several types of beholders, slimes, and mammal-ish looking creatures as well. Surprisingly however, there are no "real" dragons here. There is a race of pseudo-dragons, who are actually low intelligent reptiles that resemble dragons in basic shape only. They have no powers or abilities other than being able to stand the heat, and none have wings.