Cold weather can directly impact the cardiovascular system. “The cold weather itself makes blood vessels on the outside contract and narrow a little bit because your body is trying to protect itself and trying to keep the heat in,” explains Dr. Dow. “Because the blood vessels are narrower, the heart has to work harder to get the blood out, which can increase your blood pressure and heart rate. All of that is very stressful on the heart.”
Anyone who’s not used to that kind of stress should avoid doing physically challenging tasks in cold weather such as shoveling heavy snow. “You can go slowly, but if you have a choice, hire a high school kid to do it,” she says.
If you suffer from asthma or other respiratory conditions, be sure to cover your mouth with a heavy scarf in addition to your mask, “so that cold air doesn’t rush right into the lungs,” says Dr. Dow. “Lungs can actually spasm because there’s such a big difference in temperature. That can cause wheezing and other asthmatic symptoms.”