GREENVILLE, South Carolina, July 27 -- Duke Energy issued the following news release: Duke Energy is reminding customers to check out the latest assistance programs that can help keep bills in check as the heat of summer settles in across the Palmetto State. While summer temperatures are one cause of higher bills, the costs of fuels used to produce energy have also increased. Duke Energy does not profit from fuel costs, and the company takes steps to protect customers from spikes through long-  more