Frozen Science.In his most chilling act yet, magician David Blaine entombed Entombed, or entomb, may refer to:
Ice sculptors chiseled chis·eled or chis·elled
Made or shaped with or as if with a chisel: a finely chiseled nose.
Adj. 1. the contour of Blaine's body in two giant ice blocks and sealed him shut within the two halves. Technicians kept the frozen tomb below 0 [degrees] C (32 [degrees] F)--the temperature at which water morphs into solid ice. Shirtless, without sleep or food, Blaine stood warding off cold's deadly dangers: hypothermia hypothermia
Abnormally low body temperature, with slowing of physiological activity. It is artificially induced (usually with ice baths) for certain surgical procedures and cancer treatments. , a dramatic dip in body temperature, and frostbite frostbite (chilblains), injury to the tissue caused by exposure to cold, usually affecting the extremities of the body, such as the hands, feet, ears, or nose. Extreme cold causes the small blood vessels in the extremities to constrict. , damage or death to skin cells triggered by freezing. Luckily--or magically--Blaine emerged after 62 hours, dazed daze
tr.v. dazed, daz·ing, daz·es
1. To stun, as with a heavy blow or shock; stupefy.
2. To dazzle, as with strong light.
A stunned or bewildered condition. and confused, but unharmed.
Blaine is hardly the first human to come in from the cold. In 1997, worldclass mountaineer Heidi Howkins was buried alive by an avalanche--an enormous flood of snow --while climbing in the Himalayas. Trapped beneath a blanket of snow, Howkins, like Blaine, survived. Read on to learn more about her harrowing ordeal--and how the body combats freezing to death.
Over the past 16 years Heidi Howkins has climbed the world's highest, most perilous mountains, including Everest and K2. At more than 8,000 meters (5 miles) above sea level, winds can whip up to 161 kilometers (100 miles) per hour, and temperatures can sink to a deadly -96 [degrees] C (-140 [degrees] F). Howkins, 32, thrives on the danger. "When you climb a big mountain you're pushing yourself to the limits of survival," she says. "I actually enjoy that."
Or at least she did until May 9, 1997, when Howkins found herself merely 2,185 m (1.4 mi) from the summit of Earth's third highest peak. Forbidding Mount Kanchenjunga looms 8,586 m (5.3 mi) on the border of Nepal and India.
THRILLS AND CHILLS
Howkins' ascent went smoothly until she reached the base of a massive couloir cou·loir
A deep mountainside gorge or gully, especially in the Swiss Alps.
[French, from couler, to slide, to flow; see coulee.] (deep, icy gorge) angling upward at 70 degrees. She sensed immediate danger: snow and ice piled on slopes steeper than 22 degrees spell prime avalanche terrain. A loud noise--or climber's single misstep--can trigger a slab of snow to thunder down, accumulating masses of snow on the way. Avalanches can reach speeds up to 322 km (200 mi) per hour! (See page 12.) "Chances were nil anyone could reach me in an emergency," Howkins recalls. The nearest hospital: a four-day trek away.
But the summit beckoned her. Howkins, alone, tackled the icy wall with two ice axes and crampons (iron spikes attached to boots). She started to climb--when disaster struck. "I remember hearing a crack and a big roar," she says. Within seconds, walls of snow crumbled on top of her, sending her tumbling down the slope: "I felt like I was being tossed around in the surf."
v. smoth·ered, smoth·er·ing, smoth·ers
a. To suffocate (another).
b. To deprive (a fire) of the oxygen necessary for combustion.
2. in an ocean of ice, she couldn't move or breathe. Then Howkins blacked out. Miraculously, when she came to, she found herself on top of the snow (she suspects a second avalanche shoved her body upward). But her injuries proved serious: "I puked pink stuff, which probably means I had blood and snow in my lungs." She suffered a head gash, shattered eardrum ear·drum
The thin, semitransparent, oval-shaped membrane that separates the middle ear from the external ear. Also called drum, drumhead, drum membrane, myringa, myrinx, tympanic membrane, , and dislocated shoulder. But her biggest challenge was to simply stay warm: If she couldn't hike down the slope immediately, Howkins would freeze to death.
Even on the coldest mountain, the human body produces heat as billions of cells release energy stored in food--a process called metabolism. Blood vessels Blood vessels
Tubular channels for blood transport, of which there are three principal types: arteries, capillaries, and veins. Only the larger arteries and veins in the body bear distinct names. shuttle heat to every part of the body. But at high altitudes, the body loses heat fast. "Normally, the atmosphere pushes down on your body and wraps around it like a blanket," explains Dr. Jo Ann Pullen at St. Vincent Medical Center St. Vincent Medical Center may refer to:
If left exposed to bitter cold, the body--which consists of 50 to 70 percent water--would solidify like the block of ice that entombed Blaine. One reason Howkins survived the chill: she wore heat-trapping clothes, like long underwear made of polypropylene, a synthetic fiber designed to rapidly whisk sweat and moisture from the body. "Water pulls heat from your skin 25 times faster than air," Pullen says. "That can be dangerous for sweating climbers surrounded by snow." Howkins also dressed in layers, which helps trap pockets of warm air around her body (see photo, ANATOMY OF A CLIMBER).
Smart clothes aren't enough to help a mountain climber escape freezing to death. Like all humans, Howkins possesses an internal thermostat called the hypothalamus hypothalamus (hī'pəthăl`əməs), an important supervisory center in the brain, rich in ganglia, nerve fibers, and synaptic connections. It is composed of several sections called nuclei, each of which controls a specific function. , a peanut-size gland in the frontal region of the brain. Its job: to thermoregulate ther·mo·reg·u·late
To regulate body temperature. , or control core body temperature, at about 37 [degrees] C (98.6 [degrees] F)--regardless of external conditions. When the body gets too cold, the hypothalamus generates more heat by triggering the brain's pituitary gland pituitary gland, small oval endocrine gland that lies at the base of the brain. It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation (see endocrine system). to secrete secrete /se·crete/ (se-kret´) to elaborate and release a secretion.
To generate and separate a substance from cells or bodily fluids. hormones (chemical signals) into the blood. The hormones ensure each cell maintains a chemical balance so that the cell becomes neither too hot nor too cold.
COLD TO THE CORE
Although Howkins' core temperature remained stable as she hiked to shelter, if it had dropped by two degrees, her hypothalamus would break down, sending her body into the first stages of hypothermia (see The 3 Stages of Hypothermia). Within 10 to 15 minutes, the body's dipping temperature produces a chemical imbalance chemical imbalance Psychology A popular term of uncertain utility, which refers to a belief that many, if not all, mental disorders are attributable to a disequilibrium of one or more neurotransmitters in the cells of the brain, heart, lungs, and other vital organs. Result: organs start to malfunction. In response, blood vessels constrict con·strict
To make smaller or narrower, especially by binding or squeezing. , forcing warm blood in the arms and legs back to the organs. Meanwhile, muscles attempt to generate extra heat by shivering (tiny muscle contractions).
Once a person's temperature falls below 31.1 [degrees] C (88 [degrees] F), shivering stops--the body needs to conserve energy at all cost. The endothermic endothermic /en·do·ther·mic/ (-ther´mik) characterized by or accompanied by the absorption of heat.
en·do·ther·mic or en·do·ther·mal
1. , or heat-absorbing, chemical reactions that energize en·er·gize
v. en·er·gized, en·er·giz·ing, en·er·giz·es
1. To give energy to; activate or invigorate: "His childhood cells slow down, causing a sluggish heartbeat, clumsy muscle control, and muddled thinking. "Below 35 [degrees] C, it's very difficult for chemical reactions in your body to take place," says Pullen. "Blood thickens and stops circulating properly."
With a dwindling dwin·dle
v. dwin·dled, dwin·dling, dwin·dles
To become gradually less until little remains.
To cause to dwindle. See Synonyms at decrease. supply of oxygen-rich blood trickling to the skin, the hands and toes become prime targets for frostbite. Water inside skin cells freezes and expands, bursting open cellular membranes (thin barriers surrounding cells). As a result, burn-like blisters bubble on the skin's surface (see photo below). In severe cases, loss of blood to the outer extremities--fingers, toes, nose--causes tissues to turn black and die a condition called gangrene gangrene, local death of body tissue. Dry gangrene, the most common form, follows a disturbance of the blood supply to the tissues, e.g., in diabetes, arteriosclerosis, thrombosis, or destruction of tissue by injury. . A gangrened limb is usually amputated to halt infection.
Fortunately, Howkins was able to avoid both frostbite and hypothermia. "The key was to do everything I could, both mentally and physically, to keep myself warm." With the same extreme determination shown by magician Blaine, Howkins persevered through the pain of her injuries to reach the summit's base, just six days after the avalanche. But Howkins doesn't thank magic. Instead she admits, "I was very, very lucky."
ANATOMY OF A CLIMBER
Mountaineer Heidi Howkins' high-tech gear helps keep her warm on dangerous climbs.
ONE-PIECE GORE-TEX[TM] SUIT
Fabric designed to resist wind, sleet sleet, precipitation of small, partially melted grains of ice. As raindrops fall from clouds, they pass through layers of air at different temperatures. If they pass through a layer with a temperature below the freezing point, they turn into sleet. , and snow; wicks moisture away from body.
If Howkins' support rope breaks, she digs an ax into the snow to stop a downward slide.
Sharp boot spikes cling to steep slopes and prevent snow from caking on boot bottoms.
Ridges on light-weight sleeping pad capture small pockets of warm air to help keep the body warm.
Calf-high socks add an extra layer of insulation and keep snow out of boots.
Hard plastic shell protects against harsh weather; removable inner layer increases air circulation to reduce frostbite risk.
The 3 Stages of Hypothermia
When the body's core temperature drops to 32 [degrees] C (95 [degrees] F) or below, hypothermia sets in.
MILD: 34 [degrees] - 35 [degrees] C (93 [degrees] - 95 [degrees] F)
Body feels chilled, muscles shiver.
Seek warm shelter, replace wet clothes with dry clothes; drink hot fluids.
MODERATE: 30 [degrees] - 34 [degrees] C (86 [degrees] - 93 [degrees] F)
Shivering stops, muscles stiffen stiff·en
tr. & intr.v. stiff·ened, stiff·en·ing, stiff·ens
To make or become stiff or stiffer.
stiff , mental confusion.
Two-day hospital stay required; torso must be reheated before extremities.
SEVERE: 30 [degrees] C (86 [degrees] F
Slow pulse and breathing, loss of consciousness, increased risk of heart attack.
Emergency medical attention required! Body must reheat Re`heat´
v. t. 1. To heat again.
2. To revive; to cheer; to cherish.
Verb 1. reheat - heat again; "Please reheat the food from last night" slowly.
Social Studies: Research an expedition to one of the world's coldest places, like the Antarctic, and write a brief report on the physical challenges the expedition faced.
Did you Know?
* The danger of frostbite increases with wind, especially high winds felt by downhill skiers or mountain climbers.
* Hypothermia can occur even' at relatively mild temperatures if exposure to cold is prolonged.
* Once your core body temperature drops below 95 [degrees] F, the rate at which your brain metabolizes body sugar falls off by 3 to 5 percent every minute.
National Science Education Standards The National Science Education Standards (NSES) are a set of guidelines for the science education in primary and secondary schools in the United States, as established by the National Research Council in 1996.
Grade 5-8: personal health * structure and function in living systems * regulation and behavior
Grade 9-12: personal and community health * natural and human-induced hazards * matter, energy, and organization in living systems
"As Freezing Persons Recollect rec·ol·lect
v. rec·ol·lect·ed, rec·ol·lect·ing, rec·ol·lects
To recall to mind. See Synonyms at remember.
To remember something; have a recollection. the Snow," Outside, January 1997, p.68
K2: One Woman's Quest for the Summit by Heidi Howkins, National Geographic Books, 2001
David Blaine's Frozenin Time Web site: www.davidblaine.com/index2.html
Directions: Circle the number that best fits the sentence.
1. Mountain climbers like Heidi Howkins who scale 8,000-meter-high mountain peaks may withstand winds of up to (10 kilometers, 105 kilometers, 161 kilometers) per hour.
2. Temperatures atop high mountains can dip to (0 [degrees] C, -52 [degrees] C, -96 [degrees] C).
3. Avalanches can reach speeds of up to (100 kin, 322 kin, 453 km) per hour!
4. Water pulls heat from your skin (5, 25, 100) times faster than air.
5. Normal core body temperature is (32 [degrees] C, 35 [degrees] C, 37 [degrees] C).
CHECK FOR UNDERSTANDING, p. TE4 FROZEN SCIENCE
1. 161 kilometers
2. -96 [degrees] C
3. 322 km
5. 37 [degrees] C