Heart and Vascular Health How Cold Weather Affects Your Heart and Circulatory System By Heart and Vascular Institute, October 29, 2014 As temperatures cool down in the fall and winter months, the change in season affects your body in a variety of ways. Frigid winds make you shiver; dry air chaps unprotected lips and hands; and a lack of sunshine can even cause depression. How Cold Weather Affects the Heart Cold weather also puts immense strain on the heart. Low temperatures cause your blood vessels and arteries to narrow, restricting blood flow and reducing oxygen to the heart. Your heart must pump harder to circulate blood through the constricted blood vessels. As a result, your blood pressure and your heart rate increase. A sudden spike in blood pressure – especially when paired with outdoor exertion, such as shoveling a snowy sidewalk – can cause serious issues such as: Unstable chest pain Heart attack Stroke RELATED: What Is a Normal Heart Rate? What Is Hypothermia? Another cold weather danger is hypothermia, which is when your body temperature drops dangerously low – below 95 degrees Fahrenheit. When this happens, your heart, nervous system, and other organs cannot work properly. If left untreated, hypothermia can lead to heart and respiratory system failure and death. Symptoms of moderate to severe hypothermia include: A lot of shivering or a halt in shivering Lack of coordination Slurred speech Confusion Weak pulse Slow, shallow breathing Drowsiness Your body fights hypothermia by keeping your core as warm as possible. This causes a lack of circulation, especially to your body’s extremities like fingers and toes, which can result in frostbite. Frostbite stages There are three stages of frostbite – frostnip, superficial, and advanced. Frostnip is the mildest form and earliest stage of frostbite. It may feel like pins and needles, throbbing, aching, or numbness. The second stage of frostbite is superficial and can be identified by the skin turning white or very pale and hard. After rewarming treatment, the skin may appear blue or purple and fluid-filled blisters may appear. Severe frostbite affects all layers of skin. You may lose sensation and ability to use joints or muscles. The affected skin may turn black and hard as the tissue dies, damaging tendons, muscles, nerves, and bone. Frostnip can be treated at home by wrapping sterile dressings around the infected area. You should always seek medical attention if symptoms of superficial or severe frostbit occur. Other symptoms of frostbite include fever, dizziness, and generally feeling ill. RELATED: Hypothermia Symptoms and First Aid Treatment How to Avoid Cold Weather-related Heart Problems To help avoid any heart or circulatory system risks this winter, be sure to: Dress warmly. Although hypothermia usually takes longer to overtake the body, frostbite can occur within minutes. Be sure to cover your head, ears, fingers, and feet properly. Avoid over exertion. Take frequent rest breaks while performing physical activities outside. Stick to non-alcoholic beverages. Alcohol may make you feel misleadingly warm, causing you to underestimate your body’s actual temperature and making you more susceptible to hypothermia. If you or a loved one has heart disease, take extra measures to ensure you have a safe winter, and always seek medical attention or a doctor’s advice if you feel at risk of any of the cold weather effects. To learn more, visit the UPMC Heart and Vascular institute online or call 1-855-UPMC-HVI (876-2484) to schedule an appointment.