LOS ANGELES (CNS) — It isn’t quite summer yet, but the Southland will find itself baking in summer-like heat this week, with triple-digit record temperatures anticipated in the valleys and mountains, while even downtown could reach up to 100.

The forecast is raising fears of heat-related illnesses, strain on the power grid and the possibility of brush fires that could quickly spread in the hot and dry conditions.

The National Weather Service has already issued an excessive heat watch that will be in effect from Tuesday morning through Wednesday evening along the Los Angeles County Coast, including downtown, as well as an excessive heat watch through Friday night across the valleys and mountains.

Forecasters said the extreme heat throughout the region will create “dangerously hot conditions” with temperatures possibly reaching 113 this week in the Antelope Valley.

“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.”

For interior valleys, “hot, dry and breezy conditions” could create critical fire-danger conditions.

“There is still some uncertainty as to when the heat will relax, but there is a potential for little change through next weekend, especially for interior areas,” according the weather service.

Coastal areas will see relief a little earlier, with onshore flow expected to return by late Wednesday, bringing a return of the marine layer that will bring temperatures down.

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

The agency declared a “restricted maintenance operation” condition that will be in effect from noon to 10 p.m. Tuesday through Friday due to the forecasted high temperatures and   demand. The declaration warns that all available resources will be needed to maintain supply, and calls on suppliers to defer scheduled maintenance on generators and transmission lines if possible.

“It is still too early to know the precise impact (the) 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.”

If necessary, the ISO could issue a Flex Alert, which is a voluntary call for residents to conserve power during peak hours to reduce strain on the grid.

The NWS warned that extreme heat will “significantly increase the potential for heat-related illnesses.”

“Be prepared to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors,” according to the NWS. “Young children and pets should never be left unattended in vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.”

Also due to the heat wave, the South Coast Air Quality Management District issued an ozone advisory Monday through Saturday, predicting increased likelihood of poor air quality in many areas. Levels of ground-level ozone — the predominant summertime pollutant — are likely to reach unhealthy or higher air quality index levels throughout most of the Southland.

And, the Los Angeles County Health Officer issued a Heat Alert starting Monday and ending Wednesday for West San Fernando Valley, East San Fernando Valley, East San Gabriel Valley, Santa Clarita Valley, Antelope Valley and San Gabriel Valley — reminding everyone in those regions to take precautions to avoid heat-related illness, especially older adults, young children, outdoor workers, athletes, and people with chronic medical conditions.

Public Health issued the following recommendations to stay safe during high temperature days:

   — Drink plenty of water throughout the day;

   — Plan your day to avoid going out during the hottest hours, and wear sunscreen;

   — Wear lightweight, light-colored clothes, and wear a hat or use an umbrella;

   — Never leave children or pets in cars and call 911 if you see a child or pet in a car alone;

   — Beware of heat-related illness, like heat stroke and call 911 if you or someone you know is experiencing high body temperature, vomiting, and pale and clammy skin;

   — Check on those at risk, such as those who are sick, older adults, pregnant women, and children, and those who live alone; and

   — If you are wearing a mask, avoid strenuous workouts wearing face coverings or masks not intended for athletic purposes.

“While it is very important that everyone take special care of themselves, it is equally important that we reach out and check on others, in particular those who are especially vulnerable to the harmful effects of high temperatures, including children, the elderly, and their pets,” said Los Angeles County Health Officer Muntu Davis. “High temperatures are not just an inconvenience, they can be dangerous and even deadly.”

County and city partners operate cooling centers during times of high heat. Residents who do not have access to air conditioning are encouraged to take advantage of free cooling centers. To find a location, visit https://ready.lacounty.gov/heat/ or call 211.

Los Angeles County residents and business owners, including people with disabilities and others with access and functional needs, can call 2-1-1 for emergency preparedness information and other referral services.