Body composition may also have been relevant.

Women generally have a higher proportion of subcutaneous fat than men of comparable size, and subcutaneous fat provides insulation against heat loss.

This insulation is concentrated at the body surface, where it slows the rate of heat loss from the core to the environment.

It does not prevent surface freezing — as Jean Hilliard’s case shows, the skin and peripheral tissues froze regardless — but it may have slowed the rate at which the core itself cooled, buying additional time.

None of these factors is determinative on its own.