(Reuters) – A punishing heat wave was again forecast to bring near-record temperatures to much of the U.S. West on Monday, as a wildfire in drought-stricken Oregon continued raging out of control.

The agency that manages California’s power grid, the California Independent System Operator, issued a “flex alert” urging residents to conserve power between 4 p.m. and 9 p.m. local time on Monday, after the Bootleg Fire in Oregon disrupted electric transmission lines.

The fire had burned through more than 153,000 acres (nearly 240 square miles) as of Monday morning, mostly in Oregon’s Fremont-Winema National Forest.

Hundreds of residents in the Klamath Falls area are under mandatory evacuation orders, and the Klamath County Sheriff’s Department has begun issuing citations and will consider the unusual step of making arrests if necessary people to enforce them, county officials said.

Other states have also confronted fires amid the heat. In California along the Nevada border, the Beckwourth Complex Fire had grown to around 89,600 acres (140 square miles) as of Monday morning, with approximately 23% containment, according to the state’s fire incident reporting system.

The National Weather Service predicted additional record highs on Monday in some areas, a day after Death Valley, California, hit a scorching 130 degrees Fahrenheit (54 Celsius), one of the highest temperatures ever recorded on Earth.

But forecasters said the intense heat had likely peaked across much of the region, ahead of more seasonable temperatures later this week.

(Reporting by Joseph Ax; Editing by Aurora Ellis)