Cold (20 page)

They would laugh at me now, with all my gear and still shivering, a weak American male. If I become much colder, it will be
difficult to hold this regulator in my mouth. When I reach the surface, the first thing I see is a small waterfall, flowing
over the edge of a bluff and falling twenty feet into the ocean. The water flows from beneath a sheet of melting ice surrounded
by spruce trees, their boughs heavy with slushy, dripping snow.

In the water, large whales are less like me and more like moose and musk oxen: they are as susceptible to overheating as they
are to hypothermia. Water sucks away heat thirty times more quickly than air, but the large whales wear a coat of blubber,
far more than a sweater of fat, more like a down coat without zippers, permanently affixed. A matrix of collagen gives blubber
a spongy structure that yields to pressure but does not sag or jiggle like the fat of obesity. The stuff has the thermal conductivity
of asbestos. In mammals with thick coats of fur, the temperature rises between the outside of the coat and the skin. But the
skin of a whale is close to the temperature of the water in which the animal swims, with the temperature rising only within
the blubber, closer to the inner furnace of the whale. In the bowhead whale — a sixty-foot-long baleen whale of the far north
— the blubber can be more than two feet thick. Outside, when the whale swims between and beneath ice floes, and when it surfaces
to breathe through cracks in the ice, its skin temperature could be close to freezing, but inside the temperature holds close
to ninety-six degrees. And the blubber is vascularized, with shunts that control the amount of blood reaching the skin. The
shunts open when the whale gets hot and close when it gets cold.

The blubber is more than insulation. It streamlines the body, and near the dorsal fins and in the tail the blubber may act
as a bio-mechanical spring, storing and releasing the energy needed to flap huge flukes through thick water. The blubber floats
the whale, like an enveloping inner tube, like a diver’s buoyancy compensator.

The bowhead whale’s food generates the heat that the blubber protects. The whale swims through the water with its mouth agape,
or skims the surface, or occasionally takes a mouthful of mud. With its tongue, it squeezes the mouthful of liquid oozing
with mud and crustaceans and larval fish outward through the baleen combs that look like black, feathery plastic teeth. This
is not just any tongue, but rather a tongue of tongues, fifteen feet long and ten feet wide. The tongue squeezes out the water
and then sweeps across the bristles of keratinous baleen, the combs that pass for a sieve of teeth lining the whale’s giant
mouth, combs that may remind one of teeth but that in fact evolved from the ridges commonly found running along the roof of
the mammalian mouth, including the human mouth.

The bowhead, despite its blubber, loses something like ten thousand calories each day to the cold. The crustaceans and fish
and mud that the whale scoops from the sea are not pure fat. To get the fat it needs, the bowhead requires a hundred tons
of food each year to stay warm, plus that much again for growth, movement, and the making of little whales. To complicate
matters, the bowhead feeds for the most part during the summer and autumn, when it may consume as much as two tons of food
in a day, then diets through the winter and early spring, when food is less abundant.

For bowhead whales, the cold is not just the cold — it is ice. Swimming beneath the ice is no small risk for an air breather.
At times, the bowhead dives between openings in the ice, holding its breath, perhaps following bubble trails left by predecessors,
or looking for light penetrating down from above, or following the low-pitched rumbling calls of its brothers and sisters
and parents and cousins as it makes its way sometimes for more than a mile between surfacings. At other times, it follows
leads in the ice, long openings between two ice floes, that, as any Arctic explorer will tell you, can close with little warning.
Inupiat hunters say they have seen bowheads break through ice two feet thick. Scientists, who in comparison to Inupiat hunters
are laughably ignorant of the way of the whale and spend far too little time on the ice to see what is really going on, have
documented bowheads bashing through ice seven inches thick. And the whales have another trick: they can find a tiny airhole
and then push the ice upward, not breaking it but merely forming a hummock, a bump on the surface, into which air is sucked
and from which the animal breathes.

Also swimming under the ice are the much smaller narwhal and beluga — the tusked whale and the small white whale of the north,
both toothed whales more akin to dolphins than to the mighty crustacean-and-mud-eating baleen whales. The narwhal has been
found within three hundred miles of the North Pole, and the beluga within six hundred miles, relying on open leads in the
ice for air.

There are seals, too, out on the ice. The ringed seal is found as far north as the North Pole, living in winter beneath and
in the ice, using its foreclaws to scrape away breathing holes, maintaining bigger openings that lead to snow caves where
the animals give birth and nurse their young. In spring, they climb out on the ice to bask in the sun and to shed their fur
and replace it with new fur. They have blubber, but they also rely on fur for warmth. The individual hairs of seal fur are
flat, not round as they are in most carnivores. The flatness lets the hair lie down, streamlining the animal as it swims.

And there is the sea otter — blubberless, but with more hair per square inch than any other animal alive. Shave a square inch
of sea otter, and you will have to sweep up nearly a million hairs. Its hairs trap a layer of air, and the otter, though living
in water, is never quite wet. It wears a dry suit that actually stays dry. In exchange, it spends more than one hour in ten
preening, combing, and grooming. It sometimes lies on the surface, belly up, its nose and paws — unprotected by the fur that
covers its body — held out of the water for warmth. And like whales and seals and birds and to some degree even humans, the
sea otter isolates the warm blood of its core from the cold blood of its extremities with a rete mirabile — literally, a “wonderful
net,” a mesh of veins and arteries. The mesh is a heat exchanger. Arteries carrying warm blood from the core are surrounded
and interwoven with veins carrying cold blood from the extremities. Before the warm blood hits the extremities and gives up
its heat to the outside world, it warms the cold blood that is moving back from the extremities toward the core. Heat is conserved.
Calories are saved.

Often whales and seals and otters are the hottest things around. A Weddell seal, a thousand pounds of fur and blubber and
heart and lung and rete mirabile, might lie on the Antarctic ice, open the shunts that let warm blood flow through its blubber,
and create above it a cloud of steam. After a time, bored or hungry or spooked by a nosy human, it might flop from the ice
into the water. It might leave behind the marine mammal equivalent of a snow angel, an outline of itself melted into the ice,
a negative image of belly and fins and head in three dimensions. The Weddell seal thumbs its nose at the cold, leaving in
the ice an image that is often called a seal shadow.

It is December sixteenth, and the mercury hovers around zero near Lynx Lake, ninety miles north of Anchorage. Wind from the
north has broken the heat wave, sending the El Niño warmth scurrying south. We ski across one frozen lake after another: Ardaw,
Jacknife, Bald, Frazier, Little Frazier, Lynx. There are three of us: myself, my son, and a companion, the same woman who
joined me on Ben Nevis in September, the woman with Raynaud’s disease. Between the lakes, we ski across spits of snow-covered
land, what would be canoe portages during the summer. The snow is thin. In places, we ski on patches of exposed ice. We pass
a place where my son and I camped in August, huddled in a tent in the rain next to our canoe. Some of the lakes are joined
by frozen creeks that run through frosted peat bogs and iced-over marshes. Marsh plants sticking above the snow have sprouted
ice flowers — blossoms of white ice poking through dry brown stems. The stems, just before they freeze, hold liquid water.
As the water freezes, it expands, bursting out of the stems, forming these blossoms. The freezing water draws liquid water
behind it, and the blossoms grow. The blossoms here are the size of Ping-Pong balls, but I have heard of ice flowers as large
as baseballs.

We cross a set of moose tracks, a beaver lodge, fox tracks. I watch and listen for birds but see and hear none. The air is
still. If we stop, the world seems muffled. Sound is nothing more than changes in pressure. Pound a drum, and the air beneath
the drum is compressed and released. Speak, and the vocal cords compress air in the larynx. The compressed air moves outward
in a wave. As sound waves travel past snow, they momentarily increase the air pressure, forcing air into pores between snowflakes
and ice crystals. As the pressure of the sound waves drops, the air moves out of the pores. The air is moving in and out a
hundred times per second at a low pitch, five thousand times a second at a medium pitch, and eighteen thousand times a second
at a high pitch, near the edge of human hearing. With each movement in and out of the snow, energy is lost. The snow has swallowed
the sound. When we move, our skis drag across the snow, torturing it, making it scream with every gliding motion. At warmer
temperatures, it is more of a crunching sound, but near zero the pitch increases. It becomes more akin to the sound of fingernails
on a chalkboard. The crystal structure is stronger. What we hear is the sound of ice crystals being crushed and torn. This
screeching is the sound of hydrogen bonds unbonding under the weight and movement of our skis.

Between two lakes, we ski on a creek. The ice sounds hollow. In places, the snow has blown away, and I can see that we are
skiing on three inches of ice, under which there is six inches of air, and under the air, more ice. When the creek was freezing,
the water level was dropping. The space between is more than big enough for muskrats.

I worry as we move toward an unseen cabin. Earlier, I had trouble with the car. I had forgotten certain gear. I had expected
warmer temperatures. And I had hoped for more snow. If a breeze comes up, these cold temperatures will turn brutal. There
will be windchill, but also blowing snow, the thin layers of it lifted off the ice, sand-blasting exposed skin. I worry about
chilblains, the nasty blistering and sores that can erupt when fine blood vessels constrict in the cold and leak blood beneath
the skin. I worry about frostnip and frostbite. I worry about hypothermia and death by exposure. It was not far from here
that Andrew Piekarski died under his lawn mower, pinned to the ground while he slowly froze to death, way back in September.

And I have in my mind something J. Michael Yates, a poet and playwright, wrote of a man who “has been moving north always….
On his back he carries pack, snowshoes, and rifle.” The man dies:

A man, warmly dressed, in perfect health, mushing his dogs a short distance between two villages, never arrives. He has forgotten
to reach down, catch a little snow in his mitten, and allow it to melt in his mouth.

For a reason neither he nor his dogs understand, he steps from the runners of his sled, wanders dreamily — perhaps warmly,
pleasantly — through the wide winter, then sits to contemplate his vision, then sleeps.

The dogs tow an empty sled on to the place at one of the two villages where they’re usually fed.

While those who find the frozen man suspect the circumstances of his death, always they marvel that one so close to bed, warmth,
food, perhaps family, could stray so easily into danger.

My son, ten years old, is not worried at all. I make him stop to drink water and eat chocolate. I remind him to let me know
at the first hint of a chill, of cold toes, of stiff fingers. I want to know right away, before he becomes really cold. Later,
he complains of cold cheeks, and we stop. I check his face for patches of white, then rub my fingers across his skin looking
for hard patches, for any sign of stiffness. There is nothing.