At least two other children from a camp in Afrin, in the Aleppo countryside, were admitted to hospital with low body temperatures, according to the UN's Office for the Co-ordination of Humanitarian Affairs (Ocha).
The snowstorm hit Aleppo, which is controlled by Turkish-backed Syrian opposition forces, on Tuesday evening and continued through Wednesday night.
A video posted on Twitter by Ocha's deputy regional humanitarian co-ordinator for Syria, Mark Cutts, showed tents sagging under a heavy blanket of snow at a camp in Afrin.
“Heavy snowfall across northern Syria has blocked roads, damaged tents and made life even more difficult for displaced people in camps,” he wrote.
“The most pressing needs are reopening of the roads for uninterrupted access to the sites, moving the affected persons to safe places, securing means for heating, replacing destroyed tents, providing ready-to-eat meals and winter clothes for children and families,” the UN said in a status report on Wednesday.
The snow is expected to continue and the urgent aid response will have to continue into coming weeks, the UN said.
“One major concern is the potential floods in sites when the snow melts,” it said.
Ocha said 362 tents had been damaged across north-west Syria as of Wednesday, affecting 2,124 people in more than 420 families, who are among approximately 2 million people displaced by conflict in the country.
Khadija Suleiman, a 50-year-old mother of seven, said she rarely felt the impact of the cold weather before her family was forced to flee their home.
“We were inside our warm houses and we had money. Now we live in tents and our financial situation is difficult. We spend the entire year afraid of the coming winter. It has become a tragedy for us,” she told The National.
Faisal, a 13-year-old living in the Zaytoun camp in the southern countryside of Aleppo, said he used to love playing in the snow.
“When I was in my village, I used to enjoy it when the snow fell, but now I’m sad,” he said.
“I played with it with my friends; but not in tents. Because winter for us has become a sad time. Our tent was destroyed because of the snowfall.”
Abdelmueen Al Masri, a father of nine, said he had been unable to go out to work for a week because of the bad weather in Afrin.
“When I don’t work, I don’t even have bread to feed my kids,” Mr Al Masri, 49, told The National.
He said he earned less than $4 a day working as a lumberjack.
“I had property, land and I was well off. But it was all taken away.”