The cold nip in the air made me think of winter in the trenches and of several pictures. This first is a painting by Camille Godet of a very cold and damp looking poilu, marching somewhere.
This is a poilu trying to keep warm to eat his lunch. He has a sheepskin, a balaclava and very fancy overshoes, much to the amusement of his fellow soldiers.
A snowy patrol. I'm not sure what the poilu on the right is doing, clearing his throat or his nose?
Winter of 1939/40 and the drole de guerre, this Hotchkiss m1914 on an anti-aircraft mount, in a really heavy frost. I wonder if they actually hit anything.
(All these pictures were found on Google Search - I would like to thank the people who posted them)