Right now. Announcer from nbc news World Headquarters in new york, this is nbc nightly news with lester holt. Good evening. There are warnings tonight of a dangerous freed about to plunge a huge part of the country in its grip as the dreaded polar vortex moves south. Parts of 16 states will see temperatures below zero and windchills that make it feel a lot colder. Yes, its winter. Its february, its supposed to be cold, but as weve come to know cold snaps of this extreme can be deadly, and in this case tens of millions of people are bracing for the biggest chill so far this season. In a moment, al roker, but we begin with nbcs ron mott in boston. Reporter 65 million americans bundled up against the brutal cold as the ever present polar vortex unleashes winters harshest bite yet. The winds are like knifecutting into your friend. Reporter today the snow brought a burst of snow as far south as tennessee and the carolinas causing commuters also stranded in new york where cold weather likely contributed to train delays during rush hour. In pennsylvania, a broken water pipe left this home frosted over, and in chicago florists are taking extra care with their valentines day deliveries. Its terrible for flowers. If they are frozen, they are gone. Reporter here at fenway park the red sox are heading south to florida for spring training, giving up their home to skiers and snowboarders who are literally jumping for joy. And further north in maine the biathlon world cup left competitors with frozen faces. Record low temperatures are possible from minnesota to the midatlantic. Buffalos forecast for saturday, 2 degrees. Bostons looking at 4 below sunday morning and new york city is bracing for zero, toppling a 100yearold record, so cold in fact that saturdays annual central park ice festival cancelled. You should take this weather very, very seriously. We dont see these temperatures very often, and they can be reporter here in the boston area, the windchills are forecast to dip down to 20 to 30 below zero over the weekend, even colder in some places, as low as 40 below zero and obviously at those temperatures frostbite becomes a real concern. Doesnt take very long, as little as ten minutes. Lester. Ron mott, thanks very much. Al roker is here. Al, walk us through this. So lester, the beginning of this cold air is way up in greenland. Were talking temperatures of 60 below across the Greenland Ice sheath. Youve got low pressure over quebec and this strong low pressure system with the clockwise, counterclockwise flow around it it brings that cold air, brutally cold air into the continental united states, so low temperatures tomorrow morning, burlington minus 12, 5 in cleveland and 10 chicago and 17 in charlotte and 21 in atlanta. Highs tomorrow, 19 in new york, 13 cleveland and 14 chicago but as ron mentioned those windchills are brutal. Minus 6 in new york and minus 4 in then we bottom out on sunday morning, but the good news, lester, by tuesday temperatures rebound into the 50s and 30s. Everybody either at or above normal. All right. Al roker, thanks very much. True to predictions its getting nasty on the campaign trail in South Carolina as donald trump lobbed another socalled birther attack today threatening to sue ted cruz for, quote, not being a natural born citizen. If cruz doesnt as trump clean up his act and that battle is just one of several fronts opening up as the gop candidates sharpen their attacks on each other. Nbcs Gabe Gutierrez is on the trail in greenville, South Carolina. Autographing a baby in louisiana, republican frontrunner donald trump is now leaving a new signature on this race, threatening to sue his closest rival ted cruz for not being citizen. On twitter the billionaire calling the texas senator a liar for running negative ads against him. Theres more than a accusing anyone of being nasty given the amazing torrent of insults and obscenities and vulgarities that come out of his mouth. Reporter these voters have serious concerns about trump repeated a vulgarity at a rally this week and described him this way. Leader. Flashy. Alpha dog. Rich. Dogmatic. Narcissistic. Inspirational. Reporter cruz himself is mocking his opponent in a series of new ads, this one against marco rubio backfired. Makes me feel dumb for trusting them. Maybe you should vote for more than just a pretty face next time. Reporter Cruz Campaign yanking it after the revelation that actress had appeared in adult films. We would not have cast her had we known of that history. Reporter rubio today firing back in an exclusive interview. The bottom line is they were actor, and i think thats part of a bigger problem that ted has, and that is he tries to act like the only consistent conservative in this race. Its just not true. Political operative. Reporter all this as several gop hopefuls try to court crucial evangelical voters. Faith is the most important influence in my night. One night reading the bible i just got a serenity. Reporter tonight amid a flouriflurry of attacks serenity in this race is hard to find. The republican candidates are set to face off in another debate tomorrow. The stakes may be highest for marco rubio. Hes expected to take some of the heaviest fire, especially from his mentor and fellow Floridian Jeb bush. Lester. All right, gabe, thank you. Attacks are flying dontic side of the race with Bernie Sanders accusing Hillary Clinton of hitting him with a, quote, low blow on the debate stage last night, and a heated battle over the Different Directions they take on health care in this country. Lets get more from nbcs andrea mitchell. Reporter trying to reboot her campaign, Hillary Clinton accused Bernie Sanders of being disloyal to president obama who is minorities in the primaries and caucuses to come. The kind of criticism that weve heard from senator sanders about our president i expect from republicans. Madam secretary, that is a lo below. Reporter and she pounced on his proposed medicare for all, birthtodeath Government Health care sglan with health care, this is not about math, this is about peoples lives. The numbers dont add up, and i think once im in the white house we will have enough Political Capital to be able to do that. Secretary clinton, youre not in the white house yet and let us be clear that every proposal that i have introduced has been paid for. Reporter sanders would combine all Government Health plans into one, medicare, medicaid, veterans benefits, Childrens Health insurance and replace employerbased health care and private insurance. How to pay for it . Sanders would tax the rich. He says the middle class would pay 500 a year more in taxes, would save 5,000 a year by eliminating insurance premiums. Who is correct there are a lot of tax increases but its certainly not clear that they would be enough to pay for all the additional expenses. Reporter nonbudget partisan experts say sanders hasnt given enough details and in canada and Great Britain which have Health Care People wait months for procedures, a form of rationing. There will be tradeoffs, and if we want to save money youll have to understand that your access to Health Care May be limited. Reporter and then the political costs, Getting Congress to pass his Health Care Plan with the most bruising fight of the Obama Presidency but Bernie Sanders is calling for a political revolution, a grass roots army he believes would compel congress to accept his vision. Lester . All right, andrea, thank you. The fbi is investigating a vicious attack that took place inside a restaurant in ohio. It happened when a man pulled out a machete and went on a ramp average, slashing and stabbing people as panicked calls for help. The questions investigators are trying to answer why did he do it and could it have been an act terrorism . We get the late forest our justice correspondent pete williams. Reporter police say a man walked into this columbus restaurant around dinnertime, asked some questions and came back a short time late we are a machete. Some guy pulled out a machete and started stabbing people i ran out with my kids. There are several people injured here. Reporter some of those inside threw chairs to fight back. He ran out, drove away and was stopped after a fivemile chase. Police say he was shot and killed when he lunged holding a knife at one of them. The fbi immediately began searching the home of the man identified as the attacker, 30yearold mohammed barrie. Radical comments four years ago brought a brief look from the fbi and then moved on. Restaurant employees say when he first came in he asked where the owner is from. The owner is from israel, a christian arab. Investigators are barrie may have mistakenly thought he was jewish. Im a 50yearold man and been crying like a baby for the last 12 hours. Reporter four people were hurt, the most seriously big foley who sings at the restaurant now in critical but stable condition. Were very grateful that our victims that sustained wounds last night are all expected to recover. Reporter investigators say they dont know why barrie attacked now and shows that target, no known connections with isis. It may be one Law Enforcement official says a blend of factors, a long simmering interest in radicalism and all the attention given to terror attacks worldwide. Pete williams, nbc news, washington. The city of glendale, arizona is in shock and mourning after the shooting deaths of two 15yearold girls on a high school campus. The girls, both sophomores, died of single gunshot wounds at independence high school. A gun found beside their bodies. Police say they are not pursuing any suspects, but they if it was murder or suicide. Within a week a temporary crease fire in syria brokered with the help of the u. S. Is schedule to take effect, but key parties have been left out of the agreement announced last night. Our keir simmons now with a rare look inside syria where theres much skepticism over whether the deal will end the bloodshed. Reporter a little boy is pulled from rubble after an air strike. The video said to be in aleppo province was posted on facebook last week. Tonight there is little signs those air strikes will end, even with World Leaders including america and russia agreeing to a cessation of hostilities within one week and humidian aid to communities end siege suffering starvation. And what we have here are words on paper. What we need to see in the next few days are actions on the ground, in the field reporter major including syrian president Bashar Al Assad and the rebels fighting him are not part of the deal. Neither is isis. And today assad is vowing to retake the whole country. President assad is very visibly in control of the capital damascus while outside the city his forces are clearly on the offensive. The syrian army advancing, backed by russian air strikes. They have gained momentum, the upper hand. Why would they stop now . While in damascus few people the fighting will stop. Do you believe there will be peace now. I dont think so. I think nobody nobody knows when the peace is gone. 6yearold ayas lex were broken while in an air raid while she was out buying cookies. Shes one of tens of thousands who have fled. Those still here losing hope. Keir simmons, nbc news, damascus. A major three federal agencies about a possible danger that nbc news first reported on nearly a year and a half. The government will investigate the potential health risks from a type of turf that Children Play on all across the nation. Nbcs Stephanie Gosk has more. Reporter these soccer players, all goalies, all diagnosed with cancer, sparked a battle over the use of foam rubber, ground up car and truck tires in tens of thousands of turf field around the country. Today three federal agencies, including the epa, announced a new Research Plan to analyze the safety of crumb rubber. The existing studies do not comprehensively evaluate the concerns. Nbc news first reported on crumb rubber in october 2014. This is the stuff everybody is talking about. Reporter woman soccer coach amy griffin started asking questions after two of her goalies developed cancer, a conversation with Austin Everett who would later die of nonhodgkins lymphoma haunted her. She said i just something to do with those block dots. Reporter coach started a list of goalies with cancer which grew from just a handful to now 75 following nbcs reports. There is no research linking crumb rubber exposure to cancer, and the industry points to dozens of studies as proof that their fields are safe, but the federal government today says more reacher is needed. The three agencies will analyze chemical compounds in the crumb rubber, measure exposure to those chemicals and reach out to concerned parents, scientists and Industry Leaders. Parents like this who now the the use of crumb rubber hope that communities will hold off in installing new needs. Why not pause, use alternatives until this thing gets figured out because our children are certainly worth it. Reporter today Industry Leaders say they welcome the new research. In their words they hope the federal government can settle this matter once and for all. Lester . All right. Stephanie, thank you. Still ahead tonight, thieves after why you could be at risk without even knowing it, and one experts say you should never share with your Doctors Office in order to protect your identity. And the cost of college could be out of reach for those in this kindergarten class by the time they are old enough, b with the pain and swelling of my moderate to severe Rheumatoid Arthritis. Ordinary objects often seemed. Intimidating. Doing something simple. Meant enduring a lot of pain. If ra is changing your view of everyday things orencia may help. Orencia works differently by targeting a source of ra early in the inflammation process. For many, orencia provides longterm relief of ra symptoms. Its helped new ra patients and those not helped enough by other treatments. Do not take orencia with another biologic medicine for ra due to an increased risk of serious infection. Serious side effects can occur including fatal infections. Cases of lymphoma and lung cancer have been reported. Tell your doctor if youre prone to like an open sore, the flu, or a history of copd, a chronic lung disease. Orencia may worsen your copd. If youre not getting the relief you need. Ask your doctor about orencia. Orencia. See your ra in a different way. The flu virus hits big. With aches, chills, and fever, theres no such thing as a little flu. And it needs a big solution an antiviral. So when the flu hits, call your doctor right away and up the ante with antiviral tamiflu. Prescription tamiflu is an antiviral that attacks the flu virus at its source and helps stop it from spreading in the body. Tamiflu is fda approved to treat the flu in people two weeks of age and older whose flu symptoms started within the last two days. Before taking tamiflu, tell your doctor if youre pregnant, nursing, have Serious Health conditions, or take other medicines. If you develop an allergic reaction, a severe rash, or signs of unusual behavior, stop taking tamiflu and children and adolescents in particular may be at an increased risk of seizures, confusion, or abnormal behavior. The most common side effects are mild to moderate nausea and vomiting. Antiflu . Go antiviral with tamiflu. Hand now a warning about your most personal information as risk. Medical records being hacked, stolen and up 11,000 last year, roughly one out of every three americans has been hit, whether they know it or not, giving criminals a wealth of information that unlike compromised credit card numbers can last forever. Nbcs tom costello has what you can do to protect yourself. For john coon it was a simple xray after a snowboarding accident that turned into an accounting nightmare when the hospital billed him 20,000 for surgery he never had. I had to go down in front of the Billing Department no less and pull up my shirt and show them that i did not have any major scarring on my stomach at all. Reporter it turns out the hospitals hard drive had been stolen along with johns medical records. Just one of the 100 Million Health care records stolen last year alone. Many of those records show up for sale on the dark web where hackers openly advertise themselves and what they have stolen. This site offers fresh health care profiles stolen last april in you can use those profiles for normal fraud stuff or to get a brand new Health Care Plan for yourself. This looks very user friendly, and this is designed for crooks. This is where information from big data breeches ends up as xhomd tis are being stole. Reporter stolen credit cards going g for 1 to 3 each and Social Security numbers 15, but complete Health Care Records are a gold mines going for 60 bucks because criminals can use them to order prescriptions, pay for treatments and surgery and even file false tax returns. You basically own a person, have all the information and can you create a new account and fake his whole identity. Reporter to avoid getting hacked ibm Security Pros advise using following good work practices, dont use the same passwords and avoid giving out your Social Security numbers, even the last four digits to hospitals and Doctors Offices. You really need to push back on those look, can i give you a p. I. N. Or some piece of information that can