Photos show the true toll of California wildfires on firefighters

Since igniting a week ago the blazes have killed at least 40 people with hundreds still missing

Firefighters are still battling to bring 16 remaining fires under control (Josh Edelson/AFP/Getty)

California's firefighters have been struggling for a week now to put out the wildfires which have swept through the state.

Images of exhausted firefighters sleeping on the ground, using rocks as pillows and facing raging fires have been widely shared as the blazes take their toll.

At least 40 people have been killed and hundreds are still missing after six days of wildfires which have swept across the countryside and destroyed thousands of homes.

More than 100,000 people have been displaced in what California’s governor, Jerry Brown, has described as “one of the greatest tragedies” to ever affect the state, according to the BBC.

On Saturday powerful winds picked up overnight in the central Napa Valley causing the fires to spread and leading to residents being evacuated in Sonoma.

Despite emergency services working around the clock to contain the blazes more than 10,000 firefighters are still battling to put out 16 remaining fires.

A firefighter using a hand tool as he monitors a firing operation while a fire near Calistoga, California (Justin Sullivan/Getty Images) (Justin Sullivan/Getty)

The standard practice for firefighters in a California wildfire is to work for a 24-hour shift and then have 24 hours off, however, in this instance many have had no chance to rest for days, instead catching a few hours sleep when they get the chance, according to the New York Times.

One group of residents left behind cookies for fire crews with signs which read: “Please save our home!”

Exhausted firefighters try to get some rest on the ground using rocks as pillows (Sebastopol Fire Department/Facebook) (Sebastopol Fire Department)

Since igniting last Sunday in spots across eight counties the blazes have ripped through 220,000 acres and destroyed at least 5,700 homes and businesses.

Prisoners have been brought in to help firefighters combat the blazes (DAVID MCNEW/AFP/Getty Images) (David McNew/AFP/Getty)

Thousands of prisoners have also been brought in to fight the raging fires, with around 3,900 prisoners enrolled in the programme to join firefighters in combating the inferno.

Those involved get extra time off their sentences and earn $2 (£1) a day and $1 (75p) for each hour of active duty.

Additional reporting by The Associated Press.