Bitter cold and a tight supply of propane gas are worrying many mostly rural residents who rely on the fuel to heat their homes.
Some 7 million American households, mostly in rural areas, depend on propane for heat.
In Minnesota, the cold temperatures have forced propane prices to a 20-year high.
In Ohio and Michigan,
have relaxed some delivery restrictions to help expedite propane gas shipments.
Ohio Gov. John Kasich and Michigan Gov. Rick Snyder have loosened rules for propane shippers, allowing them to drive more hours and consecutive days than usual.
About 6 percent of Ohio households are heated primarily using propane. Periods of extreme cold have drained an already depleted supply, prompting some dealers to postpone deliveries and focus on consumers most in need.
Over the weekend, Michigan utility regulators said that Upper Peninsula residents whose supplies of propane already were running short faced new challenges this week with the closing of a Wisconsin facility for maintenance.
The Michigan Public Service Commission said inventories in the region are 43 percent below their level of one year ago.