Having worked LE in North Dakota for the last 17 years I have gained some insight to working outside in -40 weather. Our first IDPA match of the season is the 2nd Saturday of February which is usually the coldest month of the year here.
I use synthetic lube on my guns. For weapon manipulation in extreme cold gloves are a necessity, without them your hands will instantly freeze to any metal and exposed skin starts to freeze in seconds exposed to the air so frostbite is always a concern.
For short duration exposure to the extreme cold I like the Hatch Kevlar frisk gloves for shooting.
http://www.chiefsupply.com/2557-Hatc...ner-Black.aspx
My usual Patrol Gloves are thin leather insulated. As has been mentioned dress in layers. It is very comical and humbling to draw from under car-hart bibs, which is one of the many reasons for a J Frame in an outer pocket.