The National Weather Service issued heat advisories for parts of 15 states Thursday, nearly all in the South, stretching from a sliver of Southern California to North Carolina.
Thursday will be the 34th straight day of 100-plus-degree temperatures in Dallas, if the forecast holds true.
Texas set another record for electricity demand on Wednesday -- a third straight day for that distinction.
"We are expecting another record-high electricity demand (Thursday), so we are continuing our call for conservation," said Kent Saathoff with the Electric Reliability Council of Texas, which manages the state's power grid.
Temperatures reached a record high in Little Rock, Arkansas, Wednesday, soaring to a scalding 114 degrees. It's the hottest day on record for the city, according to CNN affiliate KLRT-TV.
Officials restricted high school football practices to three hours after four student athletes were hospitalized with dehydration, KLRT said.
The heat wave is taking a deadly toll across the nation, particularly on athletes, as two football players and a coach died during summer football practices this week.
DonTeria Searcy, a 16-year-old high school student, died Tuesday after he passed out after a morning practice at a Florida football camp, the local sheriff's department said.
Another 16-year-old student, Forrest Jones, died Tuesday in a hospital after he passed out during a football practice at an Atlanta-area high school, school administrators said.
And on Monday in Texas, Wade McLain, 55, an assistant football coach, collapsed during a morning practice and heat was ruled as a factor in his death, the local medical examiner's office said.
In the St. Louis suburb of Pine Lawn, Missouri, a 19-year-old woman was charged with one count of parental neglect as she, her two children and her boyfriend either passed out or fell asleep on a basketball court in the midday sun.
A passerby called 911 after spotting the four.
"The caller apparently told our officers there were four dead people in the heat on the basketball court," Pine Lawn Police Chief Rickey Collins told CNN affiliate KTVI-TV.
"This is definitely a careless situation from a parent," he said. "We're not going to go lightly on it."
In Oklahoma City, an afternoon at a water park turned unpleasant for visitors seeking a break from the blazing sun Wednesday.
Three women at the Whitewater Bay Water Park in Oklahoma were transported to a hospital after getting hit with debris kicked up by a summer storm.
"A gust of wind and a quick deluge of rain caused the injuries," said Lara O'Leary, a spokeswoman for the city's Emergency Medical Service Authority. "It happened so abruptly it took the Whitewater Bay swimmers by surprise, but the weather is, in a way, a welcome relief because we were predicted to get up to 113 here."
The injuries sustained were minor and the victims were in good condition as of Wednesday evening.
Paramedics have responded to 269 heat-related emergencies and taken 174 people to area hospitals since a heat advisory was issued on June 17, O'Leary said.
In other parts of the city, school administrators scrambled to find air-conditioned classrooms for students as systems strained under the heat wave.
Nearly 100 classrooms were without air conditioning Wednesday, said Tierney Cook-Tinnin, spokeswoman for Oklahoma City Public Schools. The school system changed its schedule this year so that students came earlier, starting Monday, the spokeswoman said.
The children have been moved out of the overheated classrooms and staff was frantically trying to fix the problem, Cook-Tinnin said.
"We've hired outside contractors to help us catch up," she said.
He went to lay down and never woke up.
wow, sorry to read Dixie...
