Our planet's polar explorers used, for the most part, Fahrenheit's scale, but rather than talking of degrees below zero, they often talked of "degrees of frost." One degree of frost was one degree below freezing Fahrenheit. An explorer might write in his journal of fifty degrees of frost -- eighteen degrees below zero Fahrenheit -- and in the next paragraph tell of the amputation of a frozen toe, or describe himself gnawing on a boot to stave off the starvation that so often accompanies cold, or mention in passing how he had to beat fifteen pounds of ice from the bottom of his sleeping bag before bedding down for the night. Or, after an especially cold and uncomfortable spell, he might write of the relative warmth and relief of fifty-five degrees below zero Fahrenheit.
Apsley Cherry-Garrard, who supported Robert Falcon Scott on his disastrous 1910 Antarctic expedition, did just that. "Now," he wrote, "if we tell people that to get only 87 degrees of frost can be an enormous relief they simply won't believe us." But an enormous relief it would be for one accustomed to camping at 75 degrees below zero, or 107 degrees of frost.
In his memoirs, Cherry-Garrard concurred with Dante, who placed the circles of ice beneath the circles of fire in his vision of Hell.