BEIJING — On a bitterly cold morning this month, Wang Fuman, 8, set out for school as he usually did, walking 2.8 miles through mountains and streams until he reached the warmth of his third-grade classroom.
When Fuman arrived two hours later, his classmates erupted in laughter. The freezing temperatures had covered his hair, eyebrows and eyelashes with frost, making him look like a snowman. His cheeks were chapped and bright red.
Fuman’s teacher at the Zhuanshanbao primary school, in the southern province of Yunnan, snapped a photograph and posted it on WeChat, a popular Chinese messaging app. Soon, the boy became an internet sensation, hailed by commenters as a symbol of the raw determination of rural residents, who make up about 43 percent of China’s population.
The state-run media called him “frost boy.”
“Heartwarming,” one user wrote on Weibo, a microblogging site. “Please don’t forget your original dreams.”
Some called him a national hero.
“Some people see beauty and hope in his simple and honest face,” one newspaper wrote. “From this little man, foreigners far away will see the great effort and strength of the Chinese nation.”
But the photo of Fuman shined a light on the plight of the tens of millions of so-called left-behind children who grow up in impoverished rural areas largely on their own after their parents leave to work in big cities. The social fabric that once held together the Chinese countryside is falling apart as millions of workers move away to chase dreams of prosperity.
Many left-behind children like Fuman live with their grandparents. They face a variety of obstacles, including malnutrition, dilapidated homes and poor access to transportation. Scores of rural schools have been shut in recent years, forcing many children to travel long distances to attend classes.
Those difficulties contribute to high dropout rates among rural children, a crisis that is hurting China’s ability to train a highly skilled work force.
“There are so many similar incidents of hardship for left-behind children in China every day,” said Kam Wing Chan, a professor at the University of Washington who studies China’s rural-urban divide.
Mr. Chan said the government could keep families together by helping them move together to large cities. But many cities impose strict rules on who qualifies for benefits like education and health care, in effect treating rural migrants as second-class citizens.
President Xi Jinping has vowed to eliminate extreme poverty by 2020, but it will not be easy. Many families live in isolated areas cut off from modern roads, schools and hospitals. While urban areas are growing rapidly richer, about 500 million Chinese, or about 40 percent of the population, live on less than $5.50 per day, according to the World Bank.
Fuman’s story drew many uplifting comments online, but it also provoked some cynicism about China’s efforts to eliminate poverty.
“We can’t solve poverty,” one Weibo user wrote, “but we can praise poverty.”
Photos of Fuman’s hands, swollen and blistered, also circulated on social media. Internet users praised his penmanship and noted the image of his hands also showed a near-perfect score on an exam.
Students at Fuman’s school told state news outlets that they lacked clothing to stay warm, and that it was common for their hair to freeze during their long commutes.
Fuman’s story prompted an influx of donations to the school and youth charities totaling at least $330,000. Local officials said they would start a program to provide winter clothes to impoverished children in the region.
In an interview with the state broadcaster China Central Television, Fuman recounted his daily journey to school. On the day that his teacher took the photo, he said, he had forgotten his hat and gloves.
Fuman and his older sister live with their grandmother, who is ill, his father, Wang Gangkui, said by telephone on Saturday. The children’s grandfather is in prison, he said.
Mr. Wang often works as a construction worker in Kunming, about 250 miles away from Fuman’s home in Ludian County. Fuman’s mother left the family two years ago, Mr. Wang said. He said he had to work far away because the family was heavily in debt.
“All the other villagers look down upon us,” he said.
Mr. Wang said he hoped for a brighter future for his children.
“I worry about them all the time,” he said. “I hope they both can make it to college and find a stable job.”
Fuman told the Chinese network CCTV that he hoped to go to a university in Beijing and become a police officer or a scientist.
“Even though I’m now an internet sensation,” he said, “I shouldn’t be proud.”