The Frostbitten Earth I is a parallel universe explored in the one-shot story arc of the same name. The universe was created by Mrs. Hannah after using Loki's Loop to grant a wish made by Austin. The POD was Matt never existing, leaving the PAAB's discovery of the Glacier undone, and allowing it to consume Earth. The universe's time sealed when Haylee Warren destroyed the in-universe Loki's Loop.
This universe's history was the same until August 1, 1996, when Matt was never born. Past this, most things were the same until the Glacier's descent on Earth. This prevented the Black Sabbath being performed on Coach Hill (known in this universe as 'Sir Salvation'), and the Order remaining under his leadership. Most of Ethel was destroyed from being crushed by ice, but not all of Ethel High School was destroyed, allowing surviving students and teachers to live in a fascist Order-run community.
After being told of the Base, Haylee decided to avenge PAAB-member Austin and try to revert the universe to how it should be, not knowing to succeed in doing so would end their reality, rather than change it. Along with fellow Association members, she launched a plan to try and retrieve the artifact that created their world. This led to the dramatic conclusion at the EHS gym, resulting in the deaths of many survivors, including every member of the Association, excluding Haylee. After violently ripping 'Sir Salvation's ear off, she destroyed Loki's Loop, ending their reailty, but also reverting the Base back to the point before Austin made the wish.
Though the universe is technically ended, it can be visited to a point prior to Haylee destroying Loki's Loop. This leads the universe open to being visited and the original fate being altered, though this has yet to be shown.