Children taking part in military-style training in snowy Nanjing, Jiangsu province, on Monday.
The session was organised by entrepreneur He Liesheng, whose extreme parenting skills have earned him the nickname "Eagle Dad", in the vein of Chinese American "Tiger Mum" Amy Chua.
Mr He favours exposing children to the winter chill to toughen up the next generation.
Four years ago, he was at the centre of a massive online controversy after he made his barely-clad son, then aged four, run in New York City's freezing February weather, China Daily reported.