The skin froze.

The muscles and subcutaneous fat in the arms and legs and face froze.

All of this is consistent with severe frostbite, which causes the same effects — rigidity, hardness, color change, and loss of sensation — in the affected tissues.

But the core — the heart, the lungs, the liver, the kidneys, the brain — appears to have been protected by the same physiological mechanism that is deliberately induced in cardiac surgery: the cold slowed everything down sufficiently that the cells could survive in a reduced-function state without sustaining permanent damage.

Dr.