Another category of hypothermia survivor is the child who falls through ice into cold water and is recovered without apparent heartbeat after an extended period underwater.

Cases of children recovered without pulse after 20, 30, or even longer minutes of submersion and subsequently resuscitated with normal brain function have been reported from cold climates around the world.

These cases rely on the rapid core cooling that cold-water submersion produces, and the protective effects of that rapid cooling on vulnerable brain tissue.

Jean Hilliard’s case is different from these cases in important ways.

Her cooling occurred through exposure to cold air rather than cold water, which produces a slower, more gradual drop in core temperature.