EL CAJON, Calif. — As a heat advisory was extended another day because of sweltering temperatures, customers crammed into local businesses Monday to find ways to cool off.

At Funky Fries and Burgers, it was is still in the mid-70s even after 10 p.m. Sales of cookie milkshakes were on the rise as customers looked for ways to beat the heat.

“Definitely inside and deliveries, milkshakes just skyrocket when it’s hot,” employee Sebastian Hallak told FOX 5.

The owners say they have been making changes to their outdoor area to deal with extreme temps this summer. They are installing more fans outside and rolled out a full new canopy to protect customers from the sun.

The restaurant has also been preparing for heat this summer by upgrading their air conditioners.

“Come in get a free shake, get some milk shakes to cool off. We’re doing our best to keep everybody cool,” says Hallak.

Right down the road, the line at Yogurt Mill was consistently out the door.

“It’s been very hot lately. It’s been hot here,” employee Isabel Bodenstadd told FOX 5. “The line has been out the door. Everyone’s been trying to get their yogurt so they don’t have to deal with the hotness so business has been really good. It helps a lot.”

Temperatures in inland were expected to be 95 to even triple digits until Tuesday.

Some customers say they came out to give their ACs a break.

“I have my second one for tomorrow so I’m good with Yogurt Mill for the next few days,” customer Mellissa Labance told FOX 5.

San Diego Gas and Electric says there are no alerts for possible blackouts at this time.

But they urge customers to conserve energy during these hot days.

SDG&E recommends people avoid using large appliances like air conditioners during peaks hours from 4 to 9 p.m.