You have to keep your skin covered too don’t you. I’ve heard it would freeze in moments if you didn’t. I suppose you have to wear some kind of covering for your eyes too. Yikes.
No exposed skin. Never touch anything at ambient temperature with unprotected skin. Even at -30, it will numb it immediately, that is if you are lucky enough for your skin to be dry. Damp or wet skin will freeze to the surface and separation will cost you skin.
Breathing hard can cause frost injuries to mucosa and even lung tissue, so you take your time, and wear something in front of your face to preheat air.
I grow a beard when it gets below -20, in advance if I am paying attention to long range forecasts, and if I do not have to be clean shaven while out on the rig (some wells the probability of encountering Hydrogen Sulfide gas is so low I can get away with it because I will not have to use breathing apparatus).
The facial hair provides a boundary static air layer which makes a huge difference, and moisture from breathing coats that with frost/ice after a little while which forms a wind-stopping protective layer on the outside of the beard for the skin underneath.
You dress in layers, the outermost to stop the wind, the others to act as insulation to keep warm. If you are very active you can shed a thin layer or two, but if you only have one thick layer you can't. The greatest danger aside from too little is too much, if you start sweating you are in trouble. Thinsulate is one of the neatest things, as it cuts the weight and bulk of those layers while increasing effectiveness, so it is easier to be warm and move, too.
Needless to say, a warm hat or some sort of head gear is necessary: 40% of your body heat escapes from your head.
Everything takes two to three times as long to do as it does when it is warm and all that isn't necessary, so it is a great opportunity to learn patience. (8^D)