Winter's latest surge has me thinking about what a beating our bodies take when the north winds blow. We've been introduced to the term, "polar vortex" this year and even people in far southern climates have been dealing with unchartered weather territory. In addition to the obvious dangers of driving in snow and ice, old man winter needs to be respected in a variety of ways when it comes to getting through the cold months.

Your body's reactions to low temperatures put a good deal of stress on the cardiovascular system. The blood vessels constrict in the skin, with the exception of your scalp, which is one reason so much body heat is lost through your head. Our blood slightly thickens and our breathing becomes shallow. To conserve heat, the muscles contract to obstruct the flow of blood to the arms and legs. This reroutes extra blood to the vital organs and increases blood pressure, putting more strain on the heart as it works harder to maintain body heat. Add exertion to this mix and you get an imbalance between supply and demand which can cause attacks of angina (chest pain) in people with heart disease. This explains why heart attacks are more common in winter.

Even people without cardio-vascular risk face issues in the cold. According to the Centers for Disease Control (CDC), about 700 deaths occur each year in the U.S. from hypothermia. Hypothermia happens when your body temperature drops to 95 degrees F or less and can be fatal if not detected promptly and treated properly. While hypothermia can happen to anyone, the elderly are at a higher risk, as their bodies don't adjust to changes in temperature quickly and they may be unaware that they are getting into trouble.

If you plan to be outdoors for an extended period of time, it's critical you dress warmly in layers and stay dry to prevent hypothermia. Wet clothing promotes heat loss. Have good hand and feet protection and a warm hat or hood. Watch for shivering, confusion, sleepiness and slurred speech, and seek medical help. If medical attention is not available, remove any wet clothing and wrap up in a warm blanket to prevent further heat loss. Warm beverages may help raise the body temperature but do not drink alcohol. Also, do not take a hot shower or bath because it can be a shock to your system. A slow warming process is best.

Warming is also important in treating frostbite, which causes a loss of feeling and color in affected areas, such as the nose, ears, fingers or toes. Frostbite can permanently damage body tissue and in severe cases require amputation. Over heating the damaged area with stoves or fireplaces can cause burns. In addition, rubbing or massaging the affected area can worsen the damage.

Signs of frostbite include reduced blood flow to hands and feet (fingers or toes can freeze), numbness, tingling or stinging, aching, and bluish or pail, waxy skin.

Asthma and other respiratory issues can worsen in the winter. Inhaling cold, dry winter air can trigger bronchospasms, which are the narrowing of air passages in the lungs.

Finally, at St. Mary's Medical Center, I see quite a few cases involving dehydration. This is especially of concern in the elderly. It's not just in the summer when we're active that we can become dehydrated. Our bodies' response to cold is very much like out bodies' response to exertion. Remember the increased blood pressure thing? Your kidneys try to lower the pressure by making more urine, requiring extra fluid intake. Dehydration can also make you more susceptible to colds and flu.

Try to cut back on caffeine and alcohol, as they contribute to fluid loss,, or at least balance your water intake with other fluids. Drink at regular intervals - especially before you go out to tackle that snow shovel.

Dr. Kenneth B. Colaric, MD, works in Emergency Medicine at St. Mary's Medical Center and can be reached at 816-655-5472.