Temperatures in the United States have reached deadly, record-breaking levels this week as some cities are reported as being colder than parts of the Antarctic.

At least nine deaths in the Midwest have been linked to the extreme weather, showing just how dangerous the "once-in-a-generation" polar vortex could be. While you keep an eye on weather updates, here are a few simple tips to stay safe and protect your health during this time. 

Choosing the right kind of clothing

When temperatures are sinking, wearing multiple layers can help preserve your core rather than wearing one thick coat. You should also make sure the layers are loose, as tight clothing can reduce circulation according to Sharon Brangman, M.D., of Upstate University Hospital, New York.

As for the material, Consumer Reports lists down wool or synthetics such as polyester, polyethylene, microfiber, and polypropylene as good options to consider. Of course, you should wear insulated shoes that are slip-proof if you might walk over icy, slippery surfaces. 

Dealing with possible frostbite

Frostbite is a condition when the skin and other tissues freeze due to low temperatures. It usually starts with a feeling numbness before the skin starts turning white or blue. If you think you may be developing frostbite, it is important to keep the area covered.

"Don’t rub your hands — if you have frost-nip or frostbite, rubbing actually causes tissue damage," Dr. Randall Wexler, a professor at Ohio State University, told ABC News. While frostnip can be treated at home, you may need to see a doctor for cases of superficial or deep frostbite.

Staying away from cigarettes, alcohol

Smokers are said to be at higher risk of frostbite as their blood vessels do not expand fast enough to provide warmth to various body parts. Researchers from Yale University also suggest that nicotine may slow down the normal response of the body to cold.

Turning to alcohol for refuge from the cold is not a good idea either. Though you may feel warm after enjoying a drink, alcohol actually lowers your core temperature and affects healthy reflexes such as the ability to shiver.

Avoiding too much of physical activity

You may have read articles about the increase in heart attacks during the holiday season. While there are a number of factors, strenuous activities like shoveling snow can be a source of sudden stress, placing a lot of strain on the heart in colder temperatures. 

Because of how drying cold air can be, you may become dehydrated more easily when performing any physical activity. Drink enough fluids and definitely limit your time outdoors as much as possible. People with diabetes, respiratory issues, heart failure etc. should speak to their doctor about any extra precautions they can take.