Triple-digit temperatures are expected as energy officials warn the electrical load on Tuesday could reach the state's highest demand ever. Four deaths were reported as multiple wildfires burned.
Power outages are increasingly common, putting everything from clean drinking water to medical equipment at risk. Some communities are installing solar power and large batteries to protect themselves.
"When you've not had power for 3 1/2 days ... you begin to question whether [blackouts] are rolling at all," says Mansfield Mayor Michael Evans.
Texas Gov. Greg Abbott deployed the Texas National Guard to move people without heat and power into shelters.
Extreme heat waves are on the rise, but California regulators didn't plan for what that would do the state's electricity grid.