No wonder those True Qi disciples had looked so terrible and were so resistant to going down into the mine to dig.
Even in the outermost areas, where the yin qi was not yet too dense, the chill was already severe. The temperature had plummeted, practically dropping straight from over twenty degrees to zero.
Once cultivators succeeded in Qi Refinement, their tolerance for environmental temperatures did indeed improve.
But that only applied to changes within a dozen or so degrees.
For instance, within a range of several degrees—and the further it dropped, the lower their tolerance became.
At the True Qi stage, they could more or less remain unafraid at around five degrees. But once it fell to around two degrees, they had to circulate their cultivation technique to ward off the invading chill.
As for zero degrees, even True Qi cultivators could still freeze to death if they remained exposed for too long.
After all, under normal circumstances, a zero-degree environment was no longer suitable for most forms of life. It was a rather harsh environment.
Even Li Su, at his current level, would begin to feel the effects once the temperature dropped below roughly minus eighty degrees.
After that, every additional drop of around five degrees would multiply that effect.
Once it went below minus one hundred degrees, he would more or less have to circulate his combat art, using his heart to speed up his blood flow and maintain his body temperature.
Foundation Establishment cultivators were roughly at the same level.
Of course, they were a little better off than Li Su. So long as it remained within the range their true astral energy could endure, they would basically be unaffected, with the cold completely cut off.
But conversely, their ability to handle sudden changes was much