ATLANTA (AP) - Stifling heat smothered states from Texas to South Carolina on Tuesday (Aug 13) with temperatures that felt like 49 deg C, making it difficult to be outside for long, much less work or play.
As the entire United States South-east baked amid heat warnings and advisories that reached from central Texas to coastal Georgia, construction workers toiled under a blazing sun in Louisiana. Meanwhile, Alabama's largest city opened its auditorium as a refuge for anyone needing to cool down.
Some schools and coaches limited football practice for players getting ready for the upcoming season, and social media was dotted with photos showing automobile thermometers with triple-digit temperature readings in degrees Fahrenheit (100 deg F is equivalent to 37.8 deg C).
Forecasters said a cold front and storms could lead to a slight midweek cool down, but for the meantime it was just too hot.
The National Weather Service said the afternoon heat index, a combination of temperature and humidity, climbed to 48.8 deg C in Clarksdale, Mississippi, nearly hitting the 49.4 deg C it felt like on Monday. Readings were nearly as high in cities including Dyersburg, Tennessee, and West Memphis, Arkansas.
In downtown Birmingham, Alabama, a piano-playing sidewalk evangelist sought refuge from the sun with two umbrellas - one over his head and the other on his sunny side.
Around the corner, artist Henry McShan sold his watercolour landscapes in a shady spot beside a park.
"I'm going to be here all day. I've got several bottles of water. I'm ready for it," said Mr McShan, his face glistening with sweat.
It was just as sizzling along the Gulf Coast in south Alabama and along the Florida Panhandle. The heat index 47 deg C before noon Tuesday in the Mobile, Alabama, area. Pensacola saw a heat index of 46.1 deg C, also before noon.
Heat exhaustion and heat stroke are prime threats during heat waves, according to the federal Centres for Disease Control and Prevention.
In Kansas, a two-year-old boy died after he was found alone in a parked car in the afternoon heat on Sunday. It appears heat played a role in the child's death, Lawrence Police Chief Gregory Burns Jr said in a statement on Monday. The heat index was 36 deg C at the time, the weather service said.
In Texas, managers of the state's main electric grid declared an energy conservation emergency and asked its customers to dial back their thermostats between 3pm and 7pm on Tuesday because of the extreme heat. The Electric Reliability Council of Texas took the action a day after it set an all-time peak demand record.
At the Dallas Zoo, where a US$1 (S$1.38) admission day was expected to draw large crowds, misting tents were set up for visitors to cool down. Elephants will be soaked with water cannons and offered frozen treats, said spokesman Chelsey Norris.
In Louisiana, road workers were urged to take precautions to protect themselves from the heat, said Ms Erin Buchanan, a spokesman with the Louisiana Department of Transportation and Development.
"Every summer, we know we're going to encounter some extreme heat," she said. "They know to take multiple breaks. They know to stay hydrated."
Heat alerts stretched as far east as the upstate area of South Carolina.
In Spartanburg, South Carolina, the Carolina Panthers and Buffalo Bills football teams practiced together before a pre-season NFL game in Charlotte, North Carolina. Over the weekend, Panthers coach Ron Rivera had some fun with Bills coach Sean McDermott, sending a screenshot of the heat index in Spartanburg, South Carolina. It showed 43 deg C along with an orange emoji face dripping with sweat.
"A psychological game," Mr Rivera joked.