Sullivan County, Tenn. -

Tennessee governor Bill Haslam joined a list of midwestern and plains governors by issuing an executive order declaring a state of emergency to keep propane trucks rolling. The order allows drivers to work longer hours to deliver.

An increased demand and transportation are driving the shortage and the price of the gas. We checked locally on our propane supplies on Tuesday.

Propane is a man-made gas that has to be brought into our region by truck or rail. The gas is pumped into delivery trucks to be delivered to homes and businesses.

It's a heat source for those living outside the metro area who can't get natural gas.

If the trucks aren't rolling, it sometimes creates shortages. "The colder it is, the trucks can't haul. So much at one time and that causes transportation problems. At one point we feel like that there might be a supply problem, which causes the price of propane to go up," Admiral Propane owner Andy Redus says.

Admiral propane seems confident that they have enough on hand to satisfy the needs of their customers like EG Sales, which offers smaller tanks to their customers. "It's unusually cold this year, and most of our propane business is in the wintertime volume-wise. We do a lot of grill tanks and things like that in the summertime, but in the wintertime it's heating," Joe Valentine with EG Sales said.

But those in the propane business tell us that the best time to buy is in the summer when the prices are down. "Over the last 10 years, we're looking at one year that if you would have bought it in the summertime you could have got a higher price. Most of the time you get a higher price in the wintertime, not the summer," Redus said.

But for their customers, the price has been consistent and not rising as in some parts of the country, because they stocked up to have adequate supplies. "We're going to be able to keep the prices where they are for the rest of the season. I know [propane companies are] taking a hit, but we work with them real close and surely it may fluctuate. Next year it's all a matter of supply and demand," Valentine said.

The severity of this year's weather will affect the supply as well.

Suppliers recommend during cold weather you should have enough propane to last the next two months.