FLU

http://www.accuweather.com/en/weathe...ses-s/21831003

RIDING IN EXTREME COLD: wear a dust mask with a breathing flap. The mask is your lungs helmet keeping cold out and warm moist lung environment in, dust out when snow melts.

Not an commonly acceptable use age in NA but in Japan.

Mask use in temps approaching zero with airborne roadside particulates should be standard.

IHS