I learned a hard lesson in cold shoveling snow for the first time in PA (dumb ol Texas boy here). I had my uninsulated rubber boots and wool socks on while shoveling (for me) an impressive 20 inches of snow. Got done, finally into the shower, and noticed a DISTINCT line across the toes…wrong color, sensitivity, all sort of bad stuff…all my fault. I took a Texas mindset into something I was not prepared for. Better socks, better boots, more awareness….nothing of the temperatures you are describing here…buy the best, an be prepared….