An online video that shows a little boy running naked in heavy snow in -13 degree New York became an online sensation, Yangtze Evening News reported.

While some people praised the boy for his toughness, some criticized his parents for being cruel.

Duoduo is seen running in his underwear in this grab from the video. [Photo from 21cn.com]

The boy's father, surnamed He, who recorded and uploaded the video, said the 4-year-old boy, Duoduo, was born premature and had a series of complications. So He designed a set of physical training and mental education programs for the boy.

He calls himself Eagle Dad, as eagles are known for their tough parenting, such as forcing their young to learn to fly.

"Now Duoduo is very healthy, he has never been to a hospital since delivery," the paper quoted He as saying.

The boy also recorded 218, a genius level, on his IQ test and has been admitted in advance to a primary school, the paper said.

"It is possible for premature babies to strengthen themselves through physical training as kids are highly adaptive," said child care experts.