^
It's funny because last winter i did exactly the contrary and was fine all winter long it's just that this time i went too far with just a summer tshirt rather than my lightweight wool top. I forgot to mention that i was wearing thin wool gloves and a wool hat just not my thin coat (in fact i remember it was my softshell cutter jacket) during the walk. It would have been impossible for me to do even 20 feet without my hands freezing. But between 0C/32F and -15C/5F all i did last winter when i was walking in town was to wear a thin wool top but kept my face, head and hands covered at all time. When temps went down a little bit further i added a thin wicking baselayer under my thin wool top and only below -20C/-4F did i brought the wool coat to walk. But at all time from 0C/32F and below my face and hands were covered. On a bicycle at -20C/-4F without a facemask on a 1hr ride i'm pretty sure i would had got sinusitis and headaches even if my whole body was pretty well used to the cold winter. So not wearing a face mask works for you but it doesn't work for me. The face mask is necessary for me and it has nothing to do with my body being used to cold or not.