I'm in Denver and went out at about 0730 to walk the dog. It was -4 here and that was hella cold. Thank God there was no wind. Still, Fido kept me out for about 25 minutes, I thought that I was going to die. I don't normally wear a face mask whilst walking to dog, just to spite Dr. Mrs. Jill Biden, but I thought about putting one on JUST for the possibility that it would warm my mouth, face, and nose.