From the introduction: This supplement conveniently lumps all wintry and frigid areas into one: "the Arctic." In your campaign, the Arctic may just be a country painted white by winter; it might be a mountain range or just a lifeless tundra. While some encounters do require the adventurers to be in the frozen wastes far to the north (or south) of proper civilization, they are nonetheless versatile. Whenever the supplement mentions "the Arctic" defer to the appropriate region in your own campaign. As you may find, there aren't even references as to whether the Arctic is in the Northern or Southern Hemisphere.