Unthinkable_ Who Survives When Disaster Strikes - and Why - Amanda Ripley [103]
Electric Cold
When Olian jumped into the water, he was wearing all his clothes, a jacket, and a wool cap, but no gloves. The water cut to the bone. “It was like getting electrocuted,” he remembers. Someone on the shore shouted to him to take the makeshift lifeline. He grabbed it and tied it around him.
Human beings do not tolerate temperature extremes very well. Other animals—like rats and pigeons—do much better. If you stick one finger in sixty-four-degree Fahrenheit water, you will feel a deep ache after about one minute. With lower temperatures, the pain comes on faster and is more intense. The water Olian jumped into was thirty-four degrees.
Here’s what it would feel like to jump into water that cold: first, your heart rate would spike. Your blood pressure would immediately shoot up. Your body would automatically reduce blood flow to the surface of the skin by constricting your blood vessels. Blood travels, so the cold blood on the surface of your skin would eventually make its way to your heart. The constriction of the blood vessels slows down that process, but it also hurts. At the same time, you may experience a sudden urge to urinate. That’s your body’s way of trying to reduce the total fluid volume in your system. Meanwhile, your heart rate would begin to fall, beating fewer times per minute until, without warming, it would eventually stop altogether.
As your skin temperature continues to cool, the pain would get worse. It would build up to an almost unbearable intensity. Then suddenly the pain would fade, and it would feel like the water had miraculously gotten warmer. In fact, in order to keep your skin supplied with oxygen, your blood vessels would have dilated, bringing a wave of blood back to the surface of your skin. That’s why your cheeks and nose look red in cold temperatures. But then, just as you’re getting more comfortable, the process would reverse itself again. The blood vessels constrict, and the pain returns. This opening and closing of the blood vessels would continue until the body becomes even colder, at which point the blood vessels would stop dilating altogether. Your blood would begin to abandon your extremities to frostbite, choosing to save your heart instead.
As soon as you entered the water, goose bumps would have popped up on your skin. Goose bumps are your hair follicles standing on end. The technical term for this is horripilation (from the Latin horrere, “to stand on end,” and pilus, which means “hair” horrible is a close relative of this word for obvious reasons). Like the rest of our survival response, it is an obvious descendant of evolution, and a classic example of how outdated our fear response can be. In animals with a lot of fur, goose bumps help to boost insulation in the cold. Or, when animals are afraid, goose bumps can bristle the animal’s coat, creating a more intimidating silhouette. But of course, humans don’t have enough hair to reap such benefits.
Meanwhile, as in any extreme situation, your abilities to reason and make decisions would deteriorate rapidly. So would your fine-motor skills. Humans lose manual dexterity in water less than fifty-four degrees. Swimming can help delay the onset of hypothermia. But as your body continued to cool you would start to shiver violently. Shivering is like involuntary calisthenics. It causes your muscles to contract, which creates heat.
Because humans have such a weakness for cold temperatures, it has been a subject of a sometimes perverse fascination for scientists for many years. In the 1930s, doctors tried treating schizophrenia and tumors with cold temperatures, under the theory that the cold might kill the diseased tissue. During World War II, Nazi scientists subjected prisoners at Dachau to atrocious experiments in temperature extremes. To this day, much of what we know about human responses to cold water comes from the suffering of these prisoners.
Like Stiley, Olian had formed an instant plan. He guessed that the water might be shallow enough that he could walk out to the survivors.