Feb. 12, 2010 -- The latest wave of snowstorms that struck snow-novice areas of Maryland and Washington D.C. has people worried about dangerous roads and highways.
But doctors also remind us of another snow-related danger: shoveling.
Studies made of the period after large snowstorms have repeatedly shown that shoveling puts people at risk for heart attacks -- even in cities experienced with snowstorms.
One storm that hit the Detroit area resulted in 36 people struck with sudden cardiac death while shoveling, according to an article published in the American Journal of Cardiology published in 2003.
Rowena Young, 78, was stunned when it happened to her husband in after a snowstorm December 2009.
"He was protecting me because he didn't want me to do it, because I had had open heart surgery and I wasn't allowed to shovel," said Young.
Otis Young, a popular local minister, who was 78, used a snow blower to clear the driveway of their Lincoln, Neb., home. But then the snowplow came down the street and left a ridge of snow at the end of their driveway that was too big for the blower and too high to drive over, so he grabbed a shovel.
"I wasn't really watching him, and it was very cold that morning. He was trying to chop the snow up so he could get out," said Young. "He came in, I thought he was fine. He hung up his shovel and his coat."
But then she heard a thump.
Young called 911, but there was nothing the first responders could do.
Doctors say they see an increase in all heart troubles following a blizzard, not just heart attacks.
Dr. Patrick McBride, professor of medicine and director of preventive cardiology at the University of Wisconsin School of Medicine in Madison, said his colleagues worked with the U.S. Centers for Disease Control and prevention to study rates of heart problems following major snowstorms.
"They found that heart attack rates go up 20 percent in the week following storms like this," said McBride.
Experts Explain Why Snow Shoveling is Deceivingly Dangerous
"I lost two friends to this activity," said Barry Franklin, director of Cardiac Rehabilitation and Exercise Laboratories at William Beaumont Hospital in Royal Oak, Mich. "It's a dangerous activity. People who are middle aged or older with a history of heart problems simply should not shovel snow."
Franklin thought many people may not realize that a shovel full of wet snow can weigh as much as 15 to 16 pounds. So he said that if someone is shoveling snow at a rate of 12 shovelfuls per minute, they will have moved nearly a ton of snow if shoveling their driveway in just 10 minutes.
"So the physical demands are really, really substantial," said Franklin.
In the past, Franklin has studied the heart rates and blood pressure of men in good physical shape who were shoveling snow. What he and his colleagues found was that the heart rates achieved by these men equaled or exceeded the heart rate that they achieved through maximal exercise testing.
"When you couple that with the cold air that they are breathing, which causes the coronary arteries to constrict, in many respects you've got a perfect storm for heart trouble," said Franklin.
"Being out in the cold, some of the warning signs may be camouflaged," he added.
Typical warning signs include pain and pressure from the navel upwards, dizziness, lightheadedness and heart palpitations.
Cold weather and hard work can mask those symptoms, delaying people's responses and sometimes leading them into more trouble.
"People can be quite short of breath and think it is just from the exertion of what they're doing. Some people could neglect to notice the arm pain [of a heart attack]," said McBride.
"We really encourage people beyond the age of 50 to try to hire a neighborhood kid to do it," he added.
Not everyone is at risk for a heart attack while shoveling, of course and people in cold climates often have "conditioning," according to Dr. Randal Thomas, director of the Mayo Cardiovascular Health Clinic in Rochester, Minn.
But Thomas worried about people in the areas hardest hit now -- areas that usually shut down after a few inches of snow.
"Snow shoveling is probably not a good first-time exercise for people who are sedentary or overweight," said Thomas, who recommended people take breaks while shoveling and try to push the snow as far as possible before lifting it.
"If they develop acute symptoms while shoveling, they should stop shoveling first and sit down and rest inside," said Thomas. "If they continue to have chest tightness or severe shortness of breath after five minutes, they should go ahead and call 911."