Stay warm! Your life may depend on it

12/18/2016, 12:13 a.m.
Baby, it's cold outside -- and many of us first feel the freezing temperatures of winter in our toes and ...
Wintry weather associated with risks for heart attacks, asthma symptoms, frostbite and hypothermia Bob Crowley/CNN

— Baby, it's cold outside -- and many of us first feel the freezing temperatures of winter in our toes and fingertips before elsewhere in the body.

This happens as your body works to protect your vital organs from the cold, said Dr. Suzanne Salamon, associate chief of clinical programs at Beth Israel Deaconess Medical Center in Boston.

"The blood vessels in all different parts of the body will constrict," she said. "They'll get smaller to try to preserve heat.

"What the body tries really hard to do is to protect the most important organs, which are the ones deep inside: the heart and brain and lungs," she said. "The body tries to keep those warm by redirecting heat from the fingers and toes inward, so the blood vessels in the fingers and toes get really small, and not enough blood goes through them."

This is important for the body to do -- and to do quickly -- because wintry weather has been associated with health risks for heart attacks, asthma symptoms, frostbite and hypothermia.

Globally, more temperature-attributable deaths tend to be caused by cold than by heat, according to a 2015 study published in the journal The Lancet.

A cold-hearted risk

Frosty weather can affect your heart, especially if you have cardiovascular disease. "You always hear about people going out and shoveling snow and having a heart attack," Salamon said.

Cold weather can act as a vasoconstrictor, which means your blood vessels narrow, and that can play a role in raising the risk of heart attack, according to a 2014 Harvard Health Letter published by Harvard Medical School.

"Snow shoveling is one example where we see people who have heart disease, or risk factors for heart disease, exerting themselves more than they may otherwise. Shoveling is hard work; people who have cardiac disease and back problems are at higher risk for injury or illness while shoveling," said Dr. Reed Caldwell, an assistant professor in the Ronald O. Perelman Department of Emergency Medicine at NYU Langone Medical Center and an emergency department physician.

A mere 1-degree Celsius reduction in temperature was associated with a cumulative 2% increased risk for heart attack, according to a 2010 study published in the British Medical Journal.

The study involved data on 84,010 hospital admissions for heart attacks in England and Wales between 2003 and 2006. The researchers analyzed the data to determine any possible relationship between outdoor temperature and heart attack occurrences.

Some other studies have also found a correlation between the winter season and heart attacks and stroke, and the phenomenon has been sometimes referred to as "Merry Christmas Coronary" and "Happy New Year Heart Attack."

However, the heart isn't the only part of the body that might be vulnerable to health problems in the winter.

Cold weather can wreak havoc on your lungs, as dry air may irritate the airways, especially for people with lung diseases such as asthma, according to the American Lung Association.

"Cold air causes bronchospasm, so people with asthma and COPD can find themselves having increased symptoms in the winter months," Caldwell said.