Shaded by a tree along Rainbow Harbor in Long Beach, Juana Perez sat on a folding chair with a hat on her head, her ice cream cart near. She jumped up to sell a couple popsicles to a family with two small children.

The heat wave expected to bring triple digits temperatures to some parts of Southern California this week has everyone looking for ways to stay cool.

Perez, who has worked in the downtown Long Beach area for about five years, travels from Fontana with other ice cream vendors to sell. Though the coast is typically cooler than her hometown, she says she prepares for the heat.

“We prepare ourselves in the morning with our hat, our chair, our cart,” Perez said in Spanish. “And then we’re ready to go for the day.”

Highs above 100 degrees in some parts of Riverside and San Bernardino counties are expected Thursday and Friday, according to the National Weather Service, which issued a heat advisory for the region in effect through 8 p.m. Thursday, July 10.

Areas in Los Angeles County’s deserts may reach the mid- to high 90s, meanwhile, with Downtown Los Angeles expected to reach 90 degrees on Thursday. Temperatures along the coast are expected to be mild.

“The mountains won’t be a cool spot, they are expected to be quite warm into the 80s,” said Casey Oswant, a meteorologist for the National Weather Service. “The coast will probably be the coolest place if people are looking to cool off.”

With few clouds lingering at the beach Thursday making for sunny conditions, temperatures along the coast will be mid- to upper 70s. Be warned – beachgoers could get a toe-numbing cool down if they dip in the water, with ocean tempertures on Wednesday showing in the low 60s due to a strong northwest wind earlier in the week that churned up colder water and displaced warmer surface water, Oswant said.

While waves got up into the 4-foot range on Wednesday, the swell should be dropping to 2 to 3 feet the next few days. Still, beachgoers should be aware of rip currents, she noted.

“People should always make sure they are talking to lifeguards before they get into the water,” Oswant said.

Coastal temperatures will be slightly cooler into the weekend and low clouds could make a return.

In the Inland Empire, the weather service warned temperatures will be in high 90s to low 100s on Thursday and Friday before cooling slightly this weekend.

The city of Riverside has nearly 20 cooling centers active in the area to assist with the heat wave. Public pools in the area opened up last month and remain open until Aug. 14 with several of them open on weekdays and Saturdays.

With San Bernardino County at a higher heat risk, officials warned that extreme heat can cause power outages and urged residents to be prepared. The increased risk of wildfire, meanwhile, led Southern California Edison last week to warn about potential public safety power shutoffs.

Temperatures are expected to hit the 90s in north Orange County this week, with inland cities such as Yorba Linda seeing some of the hottest conditions. The heat can take a toll on outdoor workers, especially greenskeepers tasked with maintaining massive stretches of grass under the sun.

At the Yorba Linda Country Club, where the par-71 course spans more than 6,800 yards, towering trees offer some shade, but it’s still grueling work.

Course superintendent Daniel Schubert, who manages the 20-person maintenance crew, said the team adjusts their schedule on hotter days to beat the worst of the heat.

“We’ll start our day around an hour earlier, around 5 a.m., to get the course prepped for play,” Schubert said.

To stay safe, Schubert said workers are encouraged to take frequent breaks and drink plenty of water. The crew also wears breathable uniforms designed for high temperatures — long sleeves made of performance fabric that cools the body while providing sun protection.

“I think you can clock it up to somewhere around three to three and a half to four miles worth of walking when we mow green. And just honestly, being in the elements, working outside, getting dirty,” he said.

To help manage the heat, he added, “We also schedule the guys in the afternoons, when the heat is stronger, doing jobs that might be a little less stressful. We try to get them in shades and obviously just continue to remind them to stay hydrated and take the breaks. It’s a tough job.”

To keep cool and stay safe during a heat wave, the NWS advises residents to drink plenty of fluids and offers the following tips:

• Opt for an air-conditioned room to stay comfortable.
• Stay out of the sun, and check up on relatives and neighbors.
• Do not leave young children and pets unattended in vehicles when car interiors can reach lethal temperatures in a matter of minutes.
• If working or spending time outside, be sure to take additional safety measures.
• When possible, reschedule strenuous activities to early morning or evening.
• Learn the signs and symptoms of heat exhaustion and heat stroke.
• Wear lightweight and loose-fitting clothing.

For information about cooling centers operated by Los Angeles, Orange, Riverside and San Bernardino counties, see LAcounty.gov/heat/, OCgov.com/cooling-centers, CAPRiverside.org/cool-centers and DPH.SBCounty.gov/extreme-heat-information-and-resources.