How hot is it in the Midwest and Southeast?
"It's hot at night, it's hot during the day, it's hot all the time," said Atlanta resident Richard Rivers."It doesn't quit."
It's so hot that triple-digit temperatures have already claimed at least 12 lives, three from Mississippi alone.
Earnestine Fields, 81, died of a heat stroke on the back porch of a relative's home in Monroe County; 48-year-old Richard Sims of Fayette collapsed and died as he was mowing his lawn.
Another Mississippi resident, Melvin Caldwell, passed away from hyperthermia, or an elevated body temperature, on Monday. It was his first day on the job as a concrete smoother in the city of Gulfport.
The heat was too much for seven puppies that died after American Airlines placed them in the cargo section of a plane. Temperatures were reportedly more than 85 degrees within the cargo, a violation of the airline's policy.
U.S. Highway 49 was forced to close its southbound lanes for hours after portions of the roadway buckled from temperatures in the low 100s near Florence, Miss.
The National Weather Service (NWS) has issued an excessive heat warning in 14 states, which aside from Mississippi include Ohio, Indiana, Arkansas and Texas. According to the organization, such a notice means that a "prolonged period of dangerously hot temperatures will occur," with heat index readings expected to peak at 110 degrees or more. Heat indices determine what the temperature feels like when taking humidity into consideration.
Most of these warnings are in effect until tomorrow evening.
Heat advisories, which mean that hot temperatures are expected in certain regions, are in effect in these states, with an additional three states instructed to take caution until later tonight. Arizona and Utah are under an excessive heat watch, while New Mexico and California are, interestingly enough, in the clear.
Cooling centers and air conditioned public buildings are opening throughout New York City tonight, which is under a heat advisory. So far, more than a quarter of a million people have visited cooling centers in the city since the heat began in June.
In Memphis, Tenn., the mercury hit 104 degrees, with firefighters going door to door urging residents to be cautious. Georgia, alone, saw humidity as high as 80 percent. Also, in Tulsa, zookeepers were feeding the animals popsicles to keep cool.
"We're just being very vigilant, making sure the animals are comfortable," said Dr. Kay Backues, a zoo veterinarian.
The NWS encourages all residents to drink plenty of fluids, stay out of the sun and check on relatives and neighbors throughout the course of the wave, especially since it is expected to continue until next week.
"It's like being in a sauna," said Capt. Mike Ward of the Tulsa Fire Department. "It can just put you down, just make you sick, all the way to death."