By CBSLA Staff

LOS ANGELES (CBSLA) — Summer-like heat is expected to bear down on the Southland next week with triple-digit temperatures anticipated in the valleys and mountains and temperatures reaching the upper 90s downtown.

Just in time for the upcoming fire danger, three Chinook helitankers have arrived to help the firefighters of Orange, Los Angeles and Ventura counties. (CBSLA)

The hot temperatures ahead raised fears Friday of heat-related illnesses, a strain on the power grid and the possibility of brush fires that could quickly spread in the hot and dry conditions.

READ MORE: School Bus Involved In Crash In Compton

The National Weather Service issued an excessive heat watch that will be in effect from Tuesday morning through Friday night across the valleys and mountains. The mountain and valley areas are expected to face “dangerously hot conditions,” with temperatures possibly reaching 109 degrees.

The watch will be in effect for the coastal region from Tuesday morning through Wednesday evening, with highs potentially reaching 98 degrees.

“Tuesday through Thursday should be the hottest, when highs between 100 and 110 and minimum humidities between 5 and 15 percent will be common over most mountains and lower mountains,” according to the NWS. “Monday night through Tuesday night is of particular concern, when north winds increase and enhance the warming and drying over the coasts and nearby valleys.”

Meanwhile, “hot, dry and breezy conditions” could create critical fire-danger conditions in interior valleys, compounded by the region’s worsening drought.

“We’re just making sure our people are prepared, they’re hydrated, our equipment is ready,” Capt. Brett Buffington of the Orange County Fire Authority said.

In Orange County, firefighters just finished up their annual classroom and field retraining with an eye on the triple digit temperatures headed to the Southland.

“The biggest thing every year is always going to be hydration, right,” Buffington said. “When it’s hot like that, we gotta stay hydrated, you gotta come in prepared that day hydrated, rested, fitness is a big thing as we come into this part of the season.”

READ MORE: Woman Shot, Critically Wounded By Long Beach School Security Officer Near Millikan High

And just in time for the upcoming fire danger, three Chinook helitankers have arrived to help the firefighters of Orange, Los Angeles and Ventura counties. The tankers are the world’s largest fire suppression choppers and can carry 3,000 gallons of fire retardant and can fly day or night.

The new “Quick Reaction Force” program, supported by nearly $18 million in funding from SoCal Edison, will launch Tuesday. It’s just one more tool SoCal crews can use to tackle remote flames like those faced during last August’s Apple Fire.

“We just hope for the best, and if the worst happens, we’ll be here and be ready,” Buffington said.

The California Independent System Operator, which manages the state’s power grid, released a statement Friday saying the agency “could take a number of actions to reduce demand and access additional energy” between Tuesday and Friday.

“It is still too early to know the precise impact that next week’s high temperatures will have on the electricity grid,” according to Cal-ISO. “But the ISO is closely monitoring conditions and the anticipated increase in demand for electricity and will issue additional public notifications as warranted.”

Due to an excessive heat forecast for the Santa Clarita Valley, the City of Santa Clarita will have its three branches of the Santa Clarita Public Library open as cooling centers beginning Tuesday, June 15.

Cooling centers will be available to the public at the following locations during the hours of 9:00 a.m. to 8:00 p.m. through Thursday, June 17, and 10:00 a.m. to 6:00 p.m. on Friday, June 18:

  • Canyon Country Jo Anne Darcy Library
    18601 Soledad Canyon Road
    Santa Clarita, CA 91351
  • Old Town Newhall Library
    24500 Main Street
    Santa Clarita, CA 91321
  • Valencia Library
    23743 W. Valencia Boulevard
    Santa Clarita, CA 91355

Members of the public are also advised that current orders in place by the Los Angeles County Department of Public Health related to COVID-19 will be enforced at these locations.

MORE NEWS: Student Fights Off Suspect In Violent Overnight Attack Near Chapman University Dorm: 'I Chased Him Back Up The Stairs, Cursing Him Out'

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)