In My Time of Dying: How I Came Face to Face with the Idea of an Afterlife

by Sebastian Junger

Low blood oxygen from hemorrhage is indistinguishable from low blood oxygen from deep cold. The body starts expending huge amounts of metabolic energy trying to stay warm—burning the furniture because it’s out of firewood, as it were. In this case, the furniture is glucose, which is stored in the body’s cells. Burning glucose instead of oxygen is a desperate short-term measure because it produces lactic acid, which in turn impairs heart function. As heart function declines, the body gets less blood and sinks further into hypothermia, which lowers oxygen levels and clotting factors in the blood even more. Low clotting factors quickly culminate in coagulopathy, where the blood can’t clot at all. This feedback loop is known as the “trauma triad of death.”