Americans have narrowly escaped a dangerous bushfire that has doubled in size and is quickly growing, as scorching heat looks set to break US temperature records.

Sky-high flames are engulfing bushland and properties in California, already ruining 10 structures – including homes – by Monday morning (Australian time).

Michelle Holcombe Young told The New Daily her mother Linda Runyan and brother Mark Holcombe escaped with “just the clothes on their back”.

Their house was destroyed by the fire and they have lost everything including precious photographs and belongings of Ms Holcombe Young’s dad who died four years ago.

Tragically, they could not save their pet dogs, Rex and Kiara.

“The fires were far enough away [when it started on Friday], but then yesterday the winds picked up and the fire just got really bad and just burned everywhere,” Ms Holcombe Young told TND.

At least 10 homes or businesses have been destroyed so far. Photo: Aleks Londoz

Ms Runyan, a 72-year-old grandmother, and Mr Holcombe, a 54-year-old truck driver, made it down the road to safety just minutes before the fire took hold of the house.

But Mr Holcombe’s arms were burnt as he fled on a four-wheel motorbike through a street appearing more like a tunnel of flames.

“All his hair is gone from both arms,” Ms Holcombe Young said.

“I didn’t know if they were alive, I had to call the sheriff’s department.

“My brother is definitely shocked and traumatised.”

California Governor Gavin Newsom has declared a state of emergency.

Mariposa fire crews filmed their route. Photo: Mariposa firefighters

The community is rallying to provide support for the 6000 evacuees and save farm animals who remain in the path of the blaze that now spans more than 55 square kilometres.

Other residents have chosen to stay and fight. They are clearing land, using lawn mowers and tractors to create fire breaks around neighbourhoods.

Mark’s pets were killed by the fire. Photo: Michelle Holcombe Young

Troy Foster told local media he was protecting the house he and his wife built after a 2008 fire destroyed their original home.

“We build this home, we worked together,” Mr Foster said.

“Sadly she passed away shortly after…so yeah it’s a pretty special home.

“I’m an old man, I live alone… I decided to stay there and do my best to make sure my house was standing when the day was done.”

Meanwhile, more than 85 million Americans had been warned to expect extraordinarily hot weather.

A 73-year-old man in Pennsylvania died of heat exposure on Saturday and authorities were concerned there could be more heatwave-related deaths by the end of the weekend.

“Numerous records highs are forecast to be tied and/or broken today in the Northeast as highs make a run at the century mark and heat indices range between 105-110 degrees,” the National Weather Service reported.

California’s emergency follows the devastating fires in southwest France and record-breaking heatwaves across Europe and Britain.

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