Dear Doctors: Our family moved from Orlando, Florida, to Boston last fall. I’m going stir crazy in the winter weather and want to try hiking. As a native Floridian, I’m good with hot weather safety. What do I need to be watching out for with cold weather exercise?
Dear Reader: The goal when spending time outdoors in any kind of weather is to keep the body’s core temperature within a fairly narrow target range. That’s because our cells play host to about a billion chemical reactions at any given second, the majority of which are highly sensitive to temperature. This is particularly true of enzymes, which are proteins that act as catalysts for essential metabolic functions. If someone’s core body temperature drops too low or rises too high, those proteins lose the 3D shape that speeds important biochemical reactions. The result is a disruption of a wide range of bodily processes crucial to health and well-being.
In the cold weather where you are planning to spend extended time, the two main risks you face are hypothermia and frostbite. Hypothermia is a condition in which core body temperature drops to 95 degrees or below. It occurs when the body begins to lose heat faster than it can produce it. Symptoms often begin with uncontrolled shivering as the body tries to generate heat with rapid muscle contractions. As the condition progresses, additional symptoms being to appear. These include impaired motor skills, slurred speech, confusion, slow heartbeat, shallow breathing and drowsiness.
Frostbite is an injury to the skin and underlying tissues caused by exposure to cold. When temperatures are extremely low, even brief exposure can result in frostbite. The body parts most at risk are the toes, fingers, ears and nose. Symptoms include skin that looks pale and feels hard, tingling or numbness that progresses to a complete loss of sensation, weakness, a loss of dexterity and blisters that develop in the hours and days after exposure.
Winter hiking enthusiasts say safety prep begins before you even leave the house. Check weather reports so you can dress appropriately, and also carry the necessary gear. Have a good trail map and know your route. Always tell someone where you’re going and when you’ll be back. Winter days are short, so plan your hike accordingly. Bring enough water and beverages to stay hydrated. It’s also important to keep those beverages warm enough that they won’t sap core body temperature. Have enough calorie-dense snacks to fuel your walk.
It’s important to dress in layers. Using your muscles generates heat, and depending on terrain, exertion and outside temperatures, how warm or cold you feel will vary throughout the hike. Overheating makes you sweat, which, as it evaporates, will chill you. So pay attention and adjust your layers as needed. If wet weather is a possibility, be sure to have a waterproof covering. Good hiking boots with grippy soles will help you stay upright on slippery ground. And don’t forget the sunscreen.
Experienced winter hikers warn against venturing out alone. Finding a local hiking group can make your winter walks safer and more enjoyable.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
