Coop,
I’ve got the full on Everest expedition gear in my truck, one of those furry hats with ear flaps (although I wear my Orange County Choppers beanie most of the time coz I look hard in that ) a few full sets of thermals and lots of clothes, including a ‘proper’ winter coat, but usually a t-shirt & hoodie are enough, if it’s super cold maybe a windproof jacket over that, but the key to staying warm is staying in the cab with the heater on
I had to lay under the trailer winding the brakes off when I ran bambi’s mum over last winter, it ripped the airlines out of all four brake chambers so I had to get creative and quickly, it was a proper winter storm, almost a white out, it would’ve been but for the wind moving the snow about, it was in the -30s and I put on my long johns, vest, a t-shirt, jumper, hoodie, waterproof/windproof jacket and trousers that zip together, gloves and my Boris hat, I could’ve slept under the trailer I was that cozy, now imagine doing that as I was dressed tonight, I would’ve slept alright…forever, it’s serious stuff the cold, you ignore it at your peril
The main thing is to cover the extremities, so gloves, hat and decent socks, then you have to stay dry, so take replacements as snow will make you wet, and don’t rush around in a panic if you do have to get out in it, at -15c and below a big gulp of air can freeze the moisture in your lungs, your core temperature will drop very quickly if you do that and a 2deg drop in that and you’re hypothermic, you fall asleep and it’s game over
It may sound all Hollywood and overdramatic, but the cold is dangerous stuff, looking cool is not an option