SAN DIEGO -- It's so hot in the West that the scorching heat is breaking records, causing massive power outages and prompting flight cancellations.
The peak may be coming Tuesday as Phoenix is expected to hit a high of 119 degrees Fahrenheit and Death Valley, California, could live up to its name, as the National Weather Service forecasts a high of 127 degrees.
Las Vegas could also see peaks on Tuesday and Wednesday, perhaps even gambling with its highest temperature ever observed, which was 117 degrees Fahrenheit in 2013.
Temperatures in San Diego County's deserts could soar as high as 122 degrees Tuesday and Wednesday as the heat wave roasting Southern California peaks.
A National Weather Service excessive heat warning for the deserts will remain in effect until 9 p.m. Thursday. A less severe heat advisory for the valleys and mountain areas with altitudes lower than 5,000 feet will expire at 9 p.m. Wednesday.
More than 29 million residents in California are under a heat warning or advisory.
Here's how the sweltering heat wave is affecting the West:
1. Some planes can't fly
The heat wave was already affecting travel in Phoenix, American Airlines canceled 43 flights Tuesday to and from Phoenix Sky Harbor Airport due to extreme heat, the airline said.
There could be more cancellations later Tuesday, an airline spokesman said. Seven flights were canceled due to weather on Monday, when the temperature reached 118 degrees, rounding out the total to 50 weather-related cancellations in two days.
Some smaller regional jets cannot take off in temperatures hotter than 117 degrees, it said in a statement.
"Our smaller regional operations -- those that use our CRJ aircraft types -- will be most affected by the heat," the airline's communication specialist Kent Powell told CNN. "We really aren't expecting any change to the operation with our mainline aircraft."
Because hotter air is thinner, planes also need more speed to take off and, thus, require more runway. Sky Harbor's runways are long enough to accommodate most planes in hot weather, American Airlines said.
2. Heat records are being shattered
-- In Phoenix, the 118 degrees on Monday tied the record set exactly a year ago.
-- On Sunday, several Northern California cities -- including Sacramento (106 degrees), San Jose (103 degrees) and San Francisco (88 degrees) -- saw record hot temperatures.
-- The record-breaking continued Monday with Sacramento hitting 107 degrees, a step hotter than its 106-degree record from 1988. It could get even hotter on Wednesday, with a forecast temperature of 109 degrees.
-- On Monday, Stockton, California, saw a record high of 109 degrees and Lancaster in southern part of the state had 110 degrees.
3. Wildfires are burning
Firefighters across California are battling several fires, including one near Big Bear spreading to 850 acres and a grass fire in Sacramento that broke out during Monday's evening commute.
Cal Fire warned of high fire danger with hot and dry conditions.
4. Power is being knocked out
Power outages have been reported over the last few days in California's Central Valley, the Bay Area and southern parts of the state.
As temperatures increase, more people turn on air conditioners, which use a lot of electricity and can strain the power system.
5. Roads buckle under the heat
The heat could've been a factor as four lanes of Highway 50 in West Sacramento began to buckle on Sunday. Drivers reported the giant cracks forming on the road and the lanes were repaired, reported CNN affiliate KGO.
How to beat the heat
Heat kills more people in the United States than any other type of weather, so take precautions.
If you can't avoid being outside and staying close to air conditioning, here's some ways to beat the heat:
-- Never leave your car locked or unattended without checking for pets and children inside. -- Hydrate with water, avoiding sugary drinks and alcohol. -- Wear light-colored clothing, which can hold down your body temperature several degrees. -- Wear sunscreen SPF 15 or higher to protect your skin from harmful UV rays. -- Don't forget to check on neighbors, friends and family, especially the young and the elderly, who are at more risk of heath damage from excessive heat.