When Nathan Hufford rolls his mobile kitchen into lunch stops or evening outdoor festivals on 100+ degree days, he knows what's in store.

"As a business owner, this is what you do," he said.

Hufford owns 'It's Nacho Truck' food truck. Inside, he has fryers, a stovetop and a steam table to keep his food warm.

"Typically, if it's about 100, 103 outside, I can usually take a meat thermometer, put it up on the shelf here," he said. "It'll be about 125."

That's dangerously hot.

At Friday's weekly Concerts in the Park event at Cesar Chavez Plaza, Hufford said, one of his employees had to go lie on the grass outside the truck to cool off. The thermometer in his truck read 121 degrees.

"You have to stay hydrated, especially in this heat," he said. "I mean, so many times you'll see people go down."

The heat didn't stop hundreds of people from attending Friday's concert. Many came equipped with water bottles.

"The heat is something that we take into account," said Jordyn Anderson.

She's the public relations specialist for Downtown Sacramento Partnership, which organizes the Concerts in the Park series, that runs every Friday, May 5 through July 21.

"This is a Sacramento summer. We're well prepared," she said. "We've been doing this for 26 years now."

The Concerts in the Park series has a new tree-shaded seating area this year, to the left of the stage.

But this stretch of high temperature days is particularly dangerous. ABC10 meteorologists say the Delta Breeze, which usually cools the Sacramento area at night, won't be coming through the area during this stretch.

"The fact that we have so many 100 degree days in a row is when we start to see more cases of heat-related illness, heat exhaustion, heat stroke," Chris Harvey, Sacramento Fire Department spokesperson, told ABC10. "The basic signs, obviously: excessive sweating, red skin. Once it starts to get worse, you're going to have nausea, vomiting, disorientation or dizziness."

Somebody showing these symptoms should receive immediate medical attention, said Harvey.

Drinking water is a key preventive step, he said -- and not just when you're heading out the door to play outside.

"You need to start drinking water the night before so that you've got plenty of water inside," said Harvey. "It's also important to do electrolyte replacement. This is especially true for the very young and the very old."

He recommends drinks like Pedialyte, Gatorade and Powerade.

"Caffeine and alcohol can exacerbate the effects of the heat," said Harvey. "They're diuretic, so if you're drinking these things on a warm day like this, you're actually going to lose more water, so if you're drinking alcohol, you want to make sure you're consuming an equal amount of water."

Concerts in the Park start at 5 p.m., which is right around the hottest time of day.

"You want to make sure you try and do your exercise, chores, yard work, that sort of stuff in the early morning hours, trying to get it done before 10 a.m," said Harvey.

There's no reason why a chord can't be struck between outdoor fun and safety this weekend and during future heat waves - as long as water and shade are part of the equation.

The U.S. Centers for Disease Control lists warning signs of heat-related illnesses HERE. Additional tips on staying safe are HERE.