Generally, cold weather is not a danger unless the skin is exposed for prolonged periods in subfreezing temperatures. Less than 20 degrees Fahrenheit is the point at which extreme caution should be taken to protect the skin from exposure, thus limiting the chances of developing frostbite. Frostbite is the freezing of the body’s tissue.
A more common condition, hypothermia, can occur in even milder temperatures and is defined as the lowering of the body’s core temperature to 95 degrees or lower. Most of your body heat is lost through your skin, and as much as 50 percent of it can be lost via your head—which is why you should always cover your head during cold weather. As the air temperature gets colder, your body compensates by shivering. The increased muscle activity generates body heat. But if the heat loss is greater than your body’s ability to generate it, then your core temperature starts to fall.
As your core temperature falls, your body compensates by shunting blood away from your skin and towards your vital organs such as your heart, lungs and brain. Of your organs, your brain and heart are the most cold-sensitive, and as your core temperature drops, the electrical activity in these organs slows.
There are many factors for determining how much caution is necessary for braving the great outdoors. The presence of wind, sunshine and humidity are chief among them. Higher humidity and sunshine help maintain heat, while wind increases heat loss and magnifies the effects of cold. Always consider the windchill factor.
Once the thermometer dips down to around 20 degrees Fahrenheit, you’ll want to use extreme caution and make sure to protect your skin from exposure, as such subfreezing temperatures dramatically increase your chances of developing frost bite.
Your cheeks, nose and ears are the most vulnerable, but your hands and feet are also easily affected. Early warning signs of frostbite include a stinging sensation, numbness or loss of feeling. If you suspect you may be developing frostbite, you’ll want to get out of the cold immediately, and slowly warm the affected area. You should NOT rub the affected area however, as this may cause skin damage.
If the numbness persists, you need to seek emergency care.
The following tips can also help you stay safe and warm while working out in the cold:
1. Dress in layers.
2. Protect your hands, feet and ears.
3. Pay attention to weather conditions and wind chill.
4. Choose appropriate gear.
Learn more about safely exercising in the cold weather at www.mayoclinic.org/fitness