They likely didn’t extract “cold” from the Mogo mines at all; if you mean how mines handle extreme temperature, the usual method is the opposite: they remove heat by pumping chilled water or ice slurry underground and using ventilation and heat exchangers to cool the air. In some mines, cold conditions can also be maintained by moving fresh outside air through shafts, but the “cold” itself isn’t mined as a resource.

What that usually means

  • Ventilation: Fresh air is pushed underground to manage temperature and fumes.
  • Chilled water or ice slurry: Cooling fluid is circulated to absorb heat.
  • Heat exchangers: These transfer heat out of mine air or water.
  • Portal heaters in very cold regions: These keep entrances from icing up while still allowing controlled airflow.

If you meant a specific story

The phrase “extract the cold” sounds like a mix-up or a nickname rather than a standard mining term. In mining, people more often talk about extracting ore , ice , or cooling energy from mine water or frozen ground, not extracting cold itself.

What the sources suggest

A mine-cooling example from South Africa describes refrigeration units producing ice/day and sending ice slurry underground to cool operations. Another source notes that deep mines can use chilled water and heat exchangers for cooling working areas.

TL;DR: They probably cooled the mine with refrigeration, ventilation, and chilled water—not by “extracting cold” from it.