Just as another blast of frigid weather swept most of the U.S., propane, the main source of heat for nearly 6 million households, is increasingly hard to find.
The shortage began last fall, when Midwestern farmers depleted stocks of the gas as they rushed to dry an unusually wet corn crop. Supply-chain problems and a surge in exports–in 2013 nearly twice as much propane was shipped overseas, where it commands higher prices, as in 2012–further tightened stocks. Since October, Midwest propane inventories are more than 5 million barrels below average, which has made the fuel scarce from Maine to Alabama.
The shortage has sent spot prices soaring nearly 30%, and elected officials have been scrambling for work-arounds. Ohio Governor John Kasich declared a state of emergency Jan. 21, and Wisconsin Governor Scott Walker followed four days later. In all, 31 states have made similar declarations. Schools in Stewart County, Tennessee, closed for five days because they didn’t have enough fuel to heat classrooms. The federal government has responded by allowing truckers hauling propane to stay on the road longer in 35 affected states. Even amid an energy boom, shortages can still occur.
This appears in the February 10, 2014 issue of TIME.