I've been into Snag in the summer, a fascinating place with a ton of history and crumbling buildings to poke around. Living in the Yukon the best I've seen is -48C / -54.5F, and I've ridden my bike to work at -43C / -45.5F.
Experiencing those temperatures is like being on another planet and I'm constantly in awe every time I get to go out and experience it.
The thing I took away from that experience is a realization that the main factor in survival is your gear.
The difference between not freezing at -10F and the same at -40 is a layer of insulation.
Don't wear anything made of cotton - it actually makes you feel colder. Throw it all out.
Wear Marino wool against your skin.
Wear multiple layers like base, mid, outer, possibly even one more when it's cold.
Spend big bucks on your base layer and outer layer. Carry multiple pairs of gloves.
After a day of activities, change all your clothes. They're damp and you don't know it.
When it's cold, don't put your bare hands on anything - the heat will be sucked out of them and it can take hours to nurse them back to good again.
Always, always, always carry a thermos of hot liquid, bomb-proof fire starting kit, and a spare change of clothes. When it's that cold, things go wrong, and you must be ready. My friend does this when only going 10 minutes from his own house. At -40C, you won't be OK for the ten minutes if you get wet or something else serious happens.
>The researchers found that under the pressure from their diamond anvil it transformed into a material that superconducted at temperatures as high as -70 °C, breaking the previous record of around -110 °C.
As the tech may improve, soon we may be able to build superconductors which will be capable of functioning on earth temperatures.
Dunking a high-Tc superconductor in a dewar of liquid nitrogen is pretty easy and relatively low cost, and I believe far more practical. I don't know that much about the diamond anvils used to generate these pressures but I believe it's only over tiny surface areas in specialised equipment.