As wildfire season in California surpasses over four million acres burn, officials are using unique ways to keep some structures safe from the flames.

Cal Fire said Sunday that more than 16,500 firefighters continue to work towards containing the 23 major wildfires currently burning across the state.

"Since the beginning of the year, there have been over 8,200 wildfires that have burned well over 4 million acres in California," the agency said in its daily update.

Red flag conditions that brought fears of gusty winds fanning the flames have subsided, but lingering warm temperatures and low humidity are still a "challenge" to fire crews, according to officials.

As of Sunday, a total of 31 people have been killed statewide in fires so far in 2020. Over 8,454 structures have also been destroyed.

Officials have taken to unique methods to keep additional structures from buildings. The U.S. Forest Service shared a glimpse at some of the preparations in Sequoia National Forest where the ongoing SQF Complex fire is burning.

In a Facebook post, officials shared an account from an unnamed firefighter describing how the Kern Canyon Ranger Station was wrapped in a protective wrap that resembled tin foil.

"The main structure stood tall in the center of the clearing, sparkling and reflecting the sunlight," the firefighter wrote. "A truly incredible sight. It had been entirely wrapped and secured in structure-wrap (similar looking to aluminum foil)."

Photos released by the Forest Service show the rustic building wrapped in what is called structure-wrap.

"Only a few more areas needed wrapping and as my crew mate and I finished the job, I couldn’t help but to feel like I was wrapping Christmas presents for my family. Each piece wrapped tight and secured with way too much tape, as my mother would say," the firefighter's account continued.

According to the Fresno Bee, the material is called structure-wrap, which is a “fire-resistant aluminum barrier which protects combustible structures” from burning embers and “radiant heat," and has also been used to save some trees in the national forest.

The state of California hit the astonishing milestone of four million acres burned on Sunday with about two months remaining in fire season. The previous record was set two years ago when wildfires destroyed 1.67 million acres.

Virtually all the damage has occurred since mid-August, when five of the six largest fires in state history erupted. Lightning strikes caused some of the most devastating blazes, with many burning in largely unpopulated land.

Many of the most destructive fires sparked in Northern California, where hills and mountains dotted with many dead trees have provided plenty of fuel for fires igniting amid high temperatures and strong winds fanning the flames. 
Thick, gray smoke from the blazes has fouled the air in many hill communities and major cities in the San Francisco Bay Area and beyond.

One of the current blazes, the Glass Fire, has been burning in Napa and Sonoma Counties for the past week.

Three fires, driven by strong winds and high temperatures, merged into one tearing into vineyards and forested mountain areas, including part of the city of Santa Rosa. Thousands of people were under evacuation orders, including the entire population of Calistoga, a town of 5,000.

The blaze came very close to Calistoga's city limits on Saturday, taking out some structures and seriously threatening the historically significant and economically important tourist hot springs and dining mecca.

"We have fire on the east of us. We have fire on the west of us creeping along. Cal Fire and all the resources doing the best they can," Calistoga Mayor Chris Canning told KTVU.

As of Sunday, the fire has scorched 63,885 acres and is 17% contained.

Numerous studies have linked bigger wildfires in America to climate change from the burning of coal, oil and gas. Scientists say climate change has made California much drier, meaning trees and other plants are more flammable.

Cal Fire said Sunday that temperatures will remain warm across the state on Sunday, but a cooling trend is expected to begin with temperatures slowly decreasing each day.

"More seasonal temperatures expected by the end of the week, with a chance of some precipitation in the most northern part of the state," the agency said.