Pat,
My hat is off to you sir!
When I was at Eielson AFB in Fairbanks, we had a heated range with Dutch doors so a person could fire standing or prone when it was cold.
I recall we even figured out how to make high tables to shoot off of and over the door.
Anything under -10*F was cold when the shooters were shooting no matter how much heat we pumped into the place.
