Dangerous Cold Can Mean Frostbite, Car Trouble The subzero cold pushing down into much of the U.S. is unlike cold weather felt in decades. The record-breaking cold is caused in part because of a "polar vortex," which one meteorologist says will send piles of polar air into the U.S. These temperatures can be dangerous, and officials in several states are warning residents to stay indoors and take precautions. "You could die if you don't respect the environment you live in," he said. Older batteries and ones that are on the verge of going dead often cannot even be jump-started once they have been exposed for an extended time to temperatures below zero. When temperatures plummet and the wind howls, ranchers have to protect themselves and their cattle in South Dakota. Bob Fortune, of Belvidere, S.D., spent part of the weekend hauling hay and other feed to his cattle to prepare them for a wind chill expected to reach 50 or 60 degrees below zero. The cattle should be fine as long as they have feed and a place to get out of the wind, he said. But with two freezing nights ahead in Louisiana, citrus farmers could lose any fruit they cannot pick in time. In Plaquemines Parish, south of New Orleans, Ben Becnel Jr. estimated that Ben & Ben Becnel Inc. had about 5,000 bushels of fruit on the trees, mostly navel oranges and the sweet, thin-skinned mandarin oranges called satsumas. Becnel said he and his 10 workers should be able to get 1,000 bushels into boxes over the next two days. "If it doesn't get below 25 for too long, some of the varieties will be OK," he said. Lemons freeze quick. The more sugar in the fruit, the longer it takes to freeze.