Officials were sending as many firefighters as they could, Cal Fire spokesman Rick Carhart said.
En route to her sister's house in Chico, she told CNN she didn't have high hopes that her home survived: "It's probably gone already".
An Associated Press photographer saw dozens businesses and homes leveled or in flames, including a liquor store and gas station.
California is experiencing one of its worst fire years ever, with 251,610 hectares burned through Sunday in areas covered by Cal Fire, almost twice the amount during the same period of 2017 and almost triple the five-year average. McLean said that by the middle of the day, there was so much smoke in the air, it looked like it was nighttime.
Video footage taken by ABC Redding affiliate KRCR showed the hospital surrounded by thick smoke as the fire illuminated the darkened sky in the background.
"It's very chaotic. It's a very bad fire", Officer Ryan Lambert of the California Highway Patrol said of the evacuation.More news: Surprise! Gabrielle Union And Dwyane Wade Welcome First Child Together
She and her husband "knocked on doors, yelled and screamed" to alert as numerous residents of 53 mobile homes and recreational vehicles as possible to leave, Bernacett said.
Cal Fire, which has been calling the wildfire Camp Fire in its incident reports, said it originated at Pulga and Camp Creek roads in Butte County. "God help us!" she said before breaking down crying.
The Butte County Sheriff's office said an evacuation order was issued for areas of Paradise, a town of about 27,000 people 180 miles northeast of San Francisco.
"We had to drive through flames to make it out safely", she said.
He confirmed reports that evacuees had to abandon their vehicles as they fled the scene. Rescuers were trying to put them in other vehicles, he said.
Cal Fire tweeted that the fire was "very dangerous" and urged people to follow evacuation orders.More news: England consult player dossier on how to defeat New Zealand
The wildfire was reported around daybreak.
A wildfire in Northern California has grown to almost 8 square miles (20 square kilometers) as officials rush to evacuate residents.
Yesterday, Cal Fire officials said that parts of Northern and Southern California was under a "red flag" warning for critical fire weather "due to gusty winds, dry fuels & low humidity".
When he arrived there, patients were out in the front of the emergency room, where the roof had caught fire.
Neighbourhoods, schools and hospitals have been evacuated while some residents in the town of Paradise were trapped by the flames, officials say.
The "Camp Fire" - as named by local officials - is expected to grow because of high winds and current dry conditions in the area.More news: France battles to save European Union digital tax proposal