(Reuters) – Firefighters made progress in surrounding a Northern California wildfire on Thursday despite searing heat, a day after the blaze triggered evacuation orders for hundreds of local residents.

The so-called Ponderosa Fire has charred nearly 3,600 acres (1,457 hectares), about 85 miles (135 km) north of the state capital of Sacramento, since it broke out on Tuesday, officials said.

It was 30 percent contained on Thursday, up from 10 percent the day before, officials said, even though temperatures in the area approached 100 degrees Fahrenheit (38 degrees Celsius).

The fire is one of several blazes in California as the state bakes in high temperatures this week. Authorities have warned the heat could fuel the existing blazes and help spark new ones.

Flames consume a garage as the Ponderosa Fire burns east of Oroville, California, U.S. August 29, 2017. REUTERS/Noah Berger

Authorities on Wednesday gave evacuation orders to residents of 500 houses and 800 outbuildings that were threatened by flames from the Ponderosa fire east of the town of Oroville.

“One of the issues we ran into on this fire is there’s a lot of people who didn’t actually evacuate,” said Paul Lowenthal, a spokesman for the team of 1,600 fighting the blaze.

The evacuation orders remained in place on Thursday, and officials opened shelters to house people.

The fire in steep and rugged terrain has destroyed 10 homes and 20 outbuildings, the California Department of Forestry and Fire Protection has said.

John Ballenger, an Oroville resident, was arrested this week on suspicion of causing the fire by starting a campfire outside a designated area and allowing it to spread out of control, officials said. He is set to appear in court on Friday.

It was not clear on Thursday evening if he had been charged. A representative for the Butte County District Attorney’s Office could not be reached for comment.

(Reporting by Alex Dobuzinskis in Los Angeles; Editing by Clarence Fernandez)