Frozen Tundra

Much of the lands near the world’s poles are barren of life because of a subfreezing climate but so too are some of its high altitude steppes and mountainous regions. The constant chill is too much for most creatures to bear, gradually sapping away their vigors until they become frozen carcasses in the snows. Every hour traveling a creature makes a DC 13 Constitution saving throw or it takes 5 (2d4) cold damage. Failure on this save by 5 or more causes a creature to gain one level of exhaustion. In exceptionally frigid areas (the peaks of the tallest mountains or right on its poles) this save is made every 10 minutes.