The National Weather Service forecasts a high of 120 degrees (49 degrees Celsius), which is has only hit three times in recorded history - the last time 22 years ago.
The problem would be more severe for smaller planes since too much heat leads to changes in the air density that make takeoff hard.
Las Vegas tied its record temperature of 117 degrees while under a massive heat dome over the U.S. Southwest, meteorologists said.
Arizona is seeing some of the most dramatic temperatures Tuesday, but the heat wave is being felt across Nevada and California, too.
At midnight on Tuesday (US time), the temperature still stood at a near-unbearable 35 degrees and the normally bustling Strip looked like the main street of a ghost town. When it comes to extreme heat, Arizona is one of the many states at risk.
The airline said the Bombardier CRJ regional aircraft can operate under a maximum temperature of 118 degrees.
Dr. Teresa Wu said emergency room patients she often sees include the elderly and people who have heart conditions, high blood pressure and kidney, liver and gastrointestinal problems. The all-time high temperature for Sky Harbor Airport was 122 degrees on June 26, 1990.
- On Sunday, several Northern California cities - including Sacramento (106 degrees), San Jose (103 degrees) and San Francisco (88 degrees) - saw record hot temperatures.
Mexico come from behind to beat New Zealand — FIFA Confederations Cup
The goal was Ronaldo's 74th of his worldwide career-the most among all active players and the national record for Portugal . Mexico plays Russian Federation and Portugal faces New Zealand on Sunday (AEST).
Larger aircraft, with wider wing-spans and more powerful engines, are not as affected by extreme temperatures. The forecast calls for a high of 118 on Monday and 120 on Tuesday in Phoenix. The study of almost 2,000 deadly heat waves worldwide since 1980 was published Monday in the journal Nature Climate Change.
The temperature in Phoenix, the capital of Arizona, reached 120 Fahrenheit degrees (about 48.8 Celsius degrees) on Tuesday, leading to the cancellation of flights in and out of the Phoenix Sky Harbor airport.
"The table was hot", he said.
The heat wave comes amid new research findings that almost 1 in 3 people now experience 20 days a year when the heat reaches deadly levels.
"Today is the peak and then tomorrow will be a little bit cooler, but we're still expecting temperatures above 115 for Phoenix", she said.
"The heat at the surface causes a wind pattern that starts to draw moisture up from the Gulf of California and from the Pacific Ocean", he said.
It's so hot in the city on Tuesday, that American Airlines cancelled almost 50 flights, due to the heat exceeding the safety limits of some of their jets.
The main burn centre in Phoenix warned people to be careful around auto interiors and pavement and with their pets. Humane societies reminded people to not let pets walk on pavement to avoid scalded paws.
"So if we didn't have these hot temperatures right now, we wouldn't have any chance for a monsoon later on in the year".
- End of the Ride: Travis Kalanick Is Done as Uber CEO
- Memorial for Muslim teen murdered in Virginia set on fire
- Bill Cosby's Lawyers Ask Judge to Declare Mistrial but Motion Is Denied
- Ruling on Dakota Access pipeline shutdown months away
- The Lehigh Valley Zoo Opens Giraffe Feeding Deck
- Check Out Pro Hockey Rumors For NHL Expansion Draft Coverage
- Paris police: Champs-Elysees attacker killed, firearms and explosives found in auto
- Corée du Nord: Washington demande à Pékin d'augmenter la pression sur Pyongyang
- Small explosion near NATO facility in Turkey; no injuries
- Police partner with Facebook for child abduction alerts