Siddharth Chatterjee, the head of the UN in China, is making waves on Chinese social media where he showcased his tough yoga and fitness exploits, including breathing exercises in sub-zero temperatures, which he says helped him to maintain physical and mental equilibrium. Mr Chatterjee, the UN Resident Coordinator for China, recently released a documentary on the efficacy of deep breathing exercises, which he said will provide immunity from viruses like COVID-19