If I were making my own, I think I'd use rigid plastic tubing, to avoid the cold weather issues.

I've experienced both lip and tongue frozen to cold metal. I have no desire to repeat either. Ever.

(Both were when I was young and stupider. The tongue was a "Would that really happen?", and the lip was on a dare, because I thought they wouldn't stick if I wiped them with my hand first. I was wrong.)