Prepare for your next Arctic adventure—or just boost your trivia skills—with these cold weather-related facts.
Seeing Isn’t Believing:
The fur of the polar bear is not actually white; each shaft of hair is actually transparent, with a hollow core. Because the hollow core scatters and reflects light, the polar bear’s coat appears white, like the ice and snow around it. In the late 1970s, three polar bears at the San Diego Zoo appeared to turn green when colonies of algae grew in their hair shafts. A zoo veterinarian restored their brilliant white appearance by killing the algae with a saline solution.
The term “Arctic” comes from the Greek word arktos (“bear”) and refers to the constellation of Ursa Major, or the Great Bear. Ursa Major dominates the sky throughout the Northern Hemisphere, but especially in its furthest northern reaches. Best known for two of its star groupings, the Big and Little Dippers, Ursa Major is a circumpolar constellation, which means it travels closely around the North Star and can be seen at any time of the year, whether high or low in the sky.
Gotta Wear Shades:
Arctic climates pose a special risk for a condition known as niphablepsia, or “snow blindness,” which occurs when unprotected eyes are exposed to ultraviolet (UV) rays of sunlight reflected by snow and ice. Such rays can burn the cornea and cause intense discomfort, including a gritty feeling beneath the eyelids, swelling and double vision. Travelers to high-altitude regions are at special risk, as the intensity of UV rays increases five percent for every 1,000 feet of elevation.
Where’s the Bathroom?:
When you’re exposed to cold weather, your blood vessels constrict, and the flow of blood to the skin is reduced, resulting in an overall slowdown of the circulatory system and a rise in blood pressure. To reduce this pressure, the body wants to get rid of as much fluid as possible through urine production. This phenomenon, known in medical terms as cold dieresis, explains why you may have to visit the bathroom more often when it’s cold.
Take the Plunge:
Fans around the globe claim that cold-water swimming has various health benefits, including stress relief, increased resistance to illnesses such as the flu and pneumonia and general regulation of the body’s internal system. Avantouinti, or “ice-swimming,” is a traditional practice that is regaining popularity in Finland; swimmers cut a hole in the ice of a frozen lake or sea and plunge in for a quick interval. Cold-water swimming organizations in the United States and Canada are known as “polar bear clubs,” while similar groups in Siberia are called “walrus clubs.”
Horripilation—the fancy scientific name for the phenomenon commonly known as “goose bumps”—is a temporary reaction of the erectores pilorum, or the tiny muscles at the base of the hair follicles covering the human body, to a stimulus such as cold, excitement or fear. When stimulated, the nervous system sends a discharge to these muscles causing them to contract, which in turn raises the follicles above the skin. Though some biologists believe that goose bumps in fur-covered animals may have evolved as part of the fight-or-flight response—to make the animals appear larger and more menacing to potential attackers—or to keep them warmer in cold weather, there appears to be little practical purpose to this phenomenon in human beings, except to make us more aware when we are cold, afraid or excited.
Life After a Cold Death:
In 2001, a 29-year-old Norwegian woman named Anna Bagenholm was skiing in northern Sweden when she lost her way and plunged into a frozen river. Her friends were able to rescue her, but only after she had been trapped beneath the ice for more than an hour and her body temperature had dropped to 56.7 degrees Fahrenheit, the lowest ever recorded. Though she was clinically dead, hospital workers were able to revive her with CPR and a special machine that used intravenous methods to warm her blood. Bagenholm eventually made a full recovery.