Demand for firewood is surging as the northern United States -- alarmed by rising heating oil prices in the aftermath of Hurricane Katrina -- braces for what could be the costliest winter on record, reported Reuters today. "Business is non-stop," said Mark Killinger, a burly 46-year-old firewood seller, pressing a foot on a freshly cut trunk of oak selling at record high prices this week. "Normally it's quiet this time of year, at least until the first frost. But this year it's very different," he said outside his 5-year-old family business in rural Maine. "People are really concerned about the cost of heating oil." He was selling firewood for as much as $225 a cord -- a stack roughly the size of a passenger car. That is up about 25 percent from last month, but fuel oil would cost about $500 for a comparable amount of heat. As Katrina relief efforts accelerate on the Gulf coast, the storm's effects are reverberating as far away as the states on Canada's border, where high fuel prices whipped up by Katrina threaten to deliver the costliest winter in memory. Many fear a reprise of last year's winter, one of the coldest on record, and are desperate to wean themselves off heating oil, which the U.S. government projected on Wednesday could rise as much as 31 percent in price this winter. --More 2358 Local Time 2058 GMT