The article began with a question implicit in the title and explicit in the opening sections: how was this possible?

The question deserves a final, honest answer.

It was possible because the cold slowed everything down — the metabolic rate, the oxygen consumption, the rate at which cells exhaust their tolerance for reduced function — to a degree that extended the window of viability far beyond what would exist at normal body temperature.

It was possible because Jean Hilliard’s body executed the physiological triage that evolution built into it: shutting down the periphery, redirecting blood to the core, maintaining the absolute minimum of core function at the cost of everything else.

It was possible because she was young and healthy, with a cardiovascular system robust enough to maintain a barely-functional rhythm at temperatures and blood flow rates that would have produced fatal arrhythmia in a less resilient system.