With classes being canceled and regular schedules being disrupted for the Martin Luther King holiday, the inauguration and with Black History Month coming up, you may feel inclined to exercise outside. Outdoor exercise in the winter can be invigorating but it carries risks as well. Here's a few DO's and DONT's for exercising when the temperature dips below forty degrees.

As always, if beginning any new physical regiment you should consult with your physician first. But assuming you are good to go, then by all means prepare yourself carefully for frigid temperatures.

DO'S

Do layer clothing. Wearing appropriate outdoor clothing is essential for a winter workout. The body can get too warm or too cold and both are bad. Layers allow the exerciser to remove clothing when perspiration starts but add clothing when chilled.

Do protect extremeties. During cold weather the body pumps blood to the body's core leaving extremities vulnerable to frostbite. Think about wearing thermal socks and using glove liners under heavier outside gloves.

Do wear appropriate gear. It can stay dark later in the morning and it gets dark earlier in the winter. Wear clothing with reflective strips so you will be visible in traffic. Roads can be slick and/or slippery so make sure shoes have good traction.

Do pay attention to wind chill factors. Wind chill is something which should be seriously considered. It can make temperatures feel signifcantly lower then they actually are. Some experts advise that when the temperature and wind chill combine and are below zero degrees exercising indoors is a better choice. And, cover your mouth with a scarf so that air can be heated before you breath it. Breathing very cold air can cause chest pains.

Do know the signs of frostbite and hypothermia. Frostbite is most common on your face, fingers and toes. Early warning signs include paleness, numbness and loss of feeling or a stinging sensation. If you suspect frostbite, get out of the cold immediately and slowly warm the affected area without rubbing. If numbness continues, seek emergency care. If you suspect hypothermia - characterized by intense shivering, slurred speech, loss of coordination and fatigue - get emergency help right away. To help prevent problems, warm your hands and feet every 20 to 30 minutes, and know when to head for home.

Do drink plenty of fluids. The body needs fluids when engaging in physical exercise. This is true whether it is hot or cold.

Do wear sunscreen. Even though its cold the sun can still be formidable. Don't forget to wear suncreen.