By Frederick Jerant

Ah, winter.

It’s the season for skiing and skating, snowball fights and fort building, sleigh rides and snowshoeing.

But in the midst of all that wintry fun, we still need to be aware of the power of cold. Just as high temperatures can adversely affect your body, so can low temperatures.

One of the simplest ways to avoid cold-weather problems is dressing properly outdoors, whether you’re working, playing or exercising.

Layers are best, says Dr. Jonathan Shingles, D. O., M. B. A., medical director of emergency medicine at St. Luke’s Hospital and Health Network’s Bethlehem campus. You can add or subtract them as needed. And cover up as much as you can, because heat can escape from any exposed skin.

The first layer is most important. It should be able to “wick” perspiration away from you, so it can evaporate through the other layers. Without that feature, you may still feel cold and clammy.

Although you can’t catch a cold by going hatless, it’s still a good idea to wear one.

Bacteria and viruses cause colds and similar illnesses, Shingles says. They’re more prevalent in the winter because we tend to be cooped up more, which increases our contact with human carriers.

“We can lose a huge percentage of body heat through our heads,” says Justin Stauffer, PA-C, a physician assistant in the Lehigh Valley Health Network’s emergency room. “The brain is on the high-priority list for blood supply, and there’s only a thin layer of bone, fat and skin to protect it from the cold. The warmer your head is, the warmer you will be.”

That’s especially important for children, Shingles adds. “Their heads are proportionally larger than the rest of their bodies,” he says, “so there can be more heat loss.”

The elderly can be more susceptible to the cold as well. “Sometimes, they can’t properly express what they’re feeling,” Shingles says. “Or they might be on medications that prevent shivering and other normal responses to cold.”

Without adequate protection, frostbite can occur—even at temperatures above 32 degrees.

Our tissues are mostly water, Shingles says. “Classically, frostbite is seen in the fingertips and other extremities, because they are further from the heart and receive less protection from the cold.” And if those body parts get cold enough, the tissues can actually freeze.

The reason for the reduced protection is simple. “The body is smart,” says Stauffer, “and it will choose life over limb. It will work to keep your liver, heart, kidneys, brain and other [core] organs warm, and it does this by shunting blood from the extremities.”

Symptoms can vary, Stauffer adds. If the “bite” is superficial, the skin will look pale and waxy. If it’s more severe, the skin looks very pale, and may even have a bluish tinge. Blisters filled with blood or other fluid may form, and the tissue itself can die.

If you suspect frostbite, get to a hospital right away. But if professional treatment isn’t readily available, (if you are not near a hospital, for example), Stauffer suggests warming the frozen part in tepid water, about 100 degrees. “Even that temperature will feel hot to the affected tissues,” he says, “so go easy.”

“Avoid letting the thawed tissue refreeze,” Shingles adds. “Repeated episodes of warming and freezing can be even more injurious.”

And never apply friction. “If ice crystals have formed, friction can break them and cause cell rupturing,” Stauffer says. “That kind of damage is nonreversible, and you could lose a finger, toe, or a limb.”

Cold weather doesn’t automatically preclude strenuous exercise like running or fitness walking, “but you should be fit in the first place,” Shingles says. “Let a doctor check you out first.”

Nevertheless, one seemingly innocuous activity can actually be fatal: snow shoveling.

“The heart works much harder in cold weather,” says Dr. Jason Fragin, D. O., a cardiologist with LVHN’s The Heart Care Group, P. C., “even if you’re in good shape.” Cold temperatures can lead the arteries to constrict, reducing blood flow to and from the heart, and there’s a higher risk of heart attacks in cold weather.

Fragin adds that there can be a substantial risk for cardiac events in those who don’t regularly exercise in any significant way, then start shoveling heavy, wet snow. He offers these helpful tips:

• Lift and toss only dry, lightweight snow.
• Just push wet and heavy snow out of the way.
• Limit yourself to 15-minute stints, followed by 30-minute breaks indoors.
• Dress warmly (hat, gloves, scarf)
• Avoid alcohol. “It dilates your arteries [allowing more blood flow], so you feel warmer, but you’re actually losing more body heat.”

And Fragin tells his open-heart surgical patients never to shovel snow. “Just hire the kid down the street,” he advises.