Seems if one has the extremities well covered/insulated and wearing thick coat, hat and pant linings, will be all right. No idea what problems the hindus really have. In those days, I always found between 10C above and 10C below outdoor quite alright(even comfortable I may say..).

I also have a niece who was born in Yellow Knife(4 degree latitude below arctic circle); there it could drop to 60C below. Amazingly that town also has a small chinese community