CHARLESTON, S.C. (AP) " Heat advisories were posted from the Carolinas to the Great Plains as the South continued to roast Friday under temperatures and humidity that made beaches feel more like bakeries.
Forecasts for Friday highs were mainly in the upper 90s to 100 throughout much of the South. The heat index, which combines humidity and temperature, was well over 100 degrees from South Carolina to eastern Oklahoma.
The National Weather Service urged people to stay out of the sun, drink fluids and get some air conditioning.
Forecasters say high humidity from the Gulf of Mexico and Atlantic is exacerbating the Southern staple of summertime heat.
The weather service issued an excessive heat warning for the South Carolina coast from Charleston into Georgia. Temperatures in the upper 90s combined with high humidity to make it feel like triple digits. Heat indices topped 100 along the coast by late morning.
A Charleston city worker who helps the elderly said one woman ran up a $600 electric bill as her small, inefficient window air conditioner ran almost nonstop to keep up with the heat.
"It's absolutely unforgiving. We have never had heat like this," said Elizabeth Spencer, who runs the Elder Support Line for the Charleston police. She said she is getting 50 phones calls a day about elderly people struggling with the oppressive heat.
It was the 11th straight day of a heat advisory or warning on the South Carolina coast, said Julie Packett, a weather service meteorologist in Charleston. She said the pattern is expected to continue through August.
In South Florida, the heat made the asphalt shimmer with mirages as the humidity weighed down the air like a stifling blanket.
Carine Weiss, who comes from the Democratic Republic of Congo, said the heat feels worse to her now than it did when she was growing up in Africa.
"I'm almost ready to pass out it's so hot," said Weiss, 47, while playing tennis with friends in Weston, Fla. "It's very hard (to play) during the summer ... I'm moving a lot slower.
Most of Alabama was under a heat advisory as temperatures in the 100-degree range were forecast for parts of the state Saturday.
Weather service meteorologist Scott Unger in Birmingham said the heat index for many parts of the state could be in the 105 to 110-degree range. He said it's a bit hotter and steamier than normal, but is a reminder of the season: "It's summertime," he said.
Associated Press writers Jeffery Collins in Columbia, S.C., Annie Greenberg in Miami, and Kendal Weaver in Montgomery, Ala., contributed to this story.
Copyright 2010 The Associated Press.