A man is tackling one of the world's most notorious races to raise money for a young resident doing it tough.
Chris Cooper is running the Marathon Des Sables in the Sahara Desert in honour of his god daughter Mae Fox.
Mr Cooper is battling searing temperatures - more than 50 degrees during the day - little sleep and a hostile environment as he completes the 157-mile run in Morocco.
It's all to raise money for a special little girl.
Little Mae, seven, has spastic quadriplegic cerebral palsy, and struggles to walk.
A broken arm last year meant Mae was immobile and chair-bound for a couple of months.
The lack of mobility set her back, and caused further tightness in her hamstrings.
The Birch Road, Cantley girl needs to raise money to head to the United States for treatment to lengthen her hamstrings.
It means the family needs to raise £20,000 to pay for flights and accommodation, treatment and special inserts for Mae's shoes.
"They put her feet in the correct position," Mae's mother Amy Fox said.
This is on top of ongoing costs to get Mae to her treatment in Scotland and England.
Amy has been following Mr Cooper's progress during the race in Africa.
"Yesterday, I stayed up until 1am to watch him come through and finish the stage," she said.
Doncaster people have been generous in donating money to the cause, Mrs Fox said.
Business SMT Xtra gave £2,500 in 2013, and followed that up with £250 last week.
The marathon numbers have steadily increased since it started in 1986. Twelve people undertook the first race.
In 2016, on the 30th anniversary of the race, 1300 people lined up at the start.