Propane prices could soar as much as 100% this winter, leaving millions of rural people to bundle up or shell out thousands of dollars to heat their homes.

The average wholesale price per gallon of propane is currently a dollar higher than this time last year, having increased from around $0.60 last October to $1.60 now, according to the Energy Information Administration. In some places, such as Mont Belvieu in Texas, the price is three times higher than in the past several years.