Before coming to Beijing, Dong's colleagues, relatives and friends collected about 70,000 yuan to help the family, and the local government added more than 1,000 yuan just a few days ago, Dong said. He also borrowed about 140,000 yuan.

To save money, he and his wife rent a room in a two-bedroom flat near the hospital at a cost of 2,700 yuan a month. They take turns caring for their son in the hospital during the day and at the apartment in the evening.

Dong's sacrifice has gained some attention on social media. Some netizens praised his actions, while others urged further improvements in medical insurance.

"I think he is a great father, as he doesn't fear losing face by dressing like a woman in the public to save his son," a netizen by the name of Qiankunchi wrote on a micro blog.

"I hope our medical insurance system can be improved so a family will not be broken by a serious disease," wrote another netizen by the name of Season.

Dong said he has not sold flowers in the past two days because he has got a cold and worries about infecting his son. "It is very cold in the underpass, but I cannot wear too much clothes under the tight robe," he said.

Dong wants to find a job in Beijing to help pay the medical bills. His salary in Linyi was about 2,600 yuan a month, he said.

"I hope I can find a part-time job, such as working in the evening, so I can also look after my son," he said. "I want to do everything I can to save my son."

Dong's wife said she feels both love and pain for her husband whenever he's out selling flowers in the cold at the underpass.

"We are sorry for our son and our only hope is he can get better," Zhao said.