| Last updated
Governor Gavin Newsom declared the state of emergency because of the 'significant heatwave' and to ease pressure on the electrical grid and avoid the problems that beset the state last year, when rolling blackouts occurred for several days during a heatwave.
Temperatures have topped 129 Fahrenheit in some places, which is around 54 degrees Celsius.
That's incredibly warm.
The state's main electrical provider, the California Independent System Operator, also issued an alert and a plea asking people to conserve electricity for five hours during peak time between 5pm and 10pm on Thursday evening.
They said: "It is necessary to take action to reduce the strain on the energy infrastructure and increase energy capacity."
Restrictions on the use of backup generators, as well as carbon fuels, fuel consumption and air cleanliness restrictions have also been rolled back temporarily while the problem is ongoing.
The provisions of the state of emergency will expire on Saturday night, although some will extend beyond that.
In a statement to Fox News, the governor's office of California said: "The proclamation suspends certain permitting requirements, allowing the use of back-up power generation and freeing up additional energy capacity to help alleviate the heat-induced demands on the state's energy grid."
The US National Weather Service has issued warnings for extreme heat in much of the Southwest USA, including not just California, but also Arizona, Nevada, and Southern Utah.
There are also heat warnings for central areas such as Kansas, Iowa, Missouri, and Nebraska.
National Weather Service forecaster Bob Oravec told Reuters: "It's a pretty big impact with respect to where the record heat is.
"But now the temperatures in the last several days, especially today, are going anywhere from 10 to 20 degrees above average."
Of course, it's pretty hot there usually at this time of year, but this is getting ridiculous now.
The area is supposed to be in around 100 degrees Fahrenheit now, but the temperatures of more than 120 are causing serious problems.
Regions within the state of California are now also starting to open cooling centres to help those who are struggling in the high temperatures.
It also means that people are cranking their air conditioning units, which is why they've been asked to conserve energy where possible.
Elliot Mainzer, chief executive of the California ISO, said: "The public's help is essential when extreme weather or other factors beyond our control put undue stress on the electric grid."
Chosen for YouChosen for You
Most Read StoriesMost Read