Wool base layer, insulated mid layer, rain/windproof outer shell. They key here is too add/remove layers as needed, dictated by the weather and how active you're being at the moment.

I work outside during all seasons.

In the winter…

Layers. Layers. Layers.

Top half:

• Undershirt(or not - depends on how cold).
• Thermal long sleeve.
• T-Shirt.
• Hoodie.
• Jacket(or not - depends on activity level)

Bottom half:

• Spandex type briefs.
• Thermal Long Johns.
• Thick work pants (carhart/dakota/etc)
• Decent wool/cotton blend socks.
• Snow pants(or not, slush pants or full bib - depends on snow and temps)

just put your hands between your buttocks. That's nature's pocket. -Futurama

If you’re active outside it’s surprisingly hard to be cold to be honest. Beyond that the most important thing is having a wind proof layer on the outside, and probably some decent gloves.

Carhart overalls (knock off brands might or might not be good). A good sweatshirt. Unzip or remove as needed - different parts of the day and different activities demand different levels of outwear. At the end of the day find all the clothes you shed and pack them back home for the next days.

For chilly days the cheap "jersey" gloves work great: buy a case. You need a new pair every day, but they are thin enough that they are easy to work in and cheap enough that you don't care about a new pair daily. For cold days the yellow "chore gloves" work great, keep a dozen around so you can switch when they get wet. Most of the time I just let them air dry in my car.

Only really cold days have breakfast and start later in the day.

The only think I can't help you with is when it is -1C and raining. If at all possible stay home.

Everyone here is correct, lots of layers and wool. The only exception is cold windy days, it's damn difficult to prepare for wind. On a -40 windy day there's not a lot you can do. Hand warmers, or even better heated gloves can be amazing on those days for when you just can't get your hands warm. My girlfriend uses a heated vest regularly and she loves it. I also almost always have a large thermos of hot soup or tea to sip on on break.

On stupid cold days I'll sometimes where two wool baselayers. I find the layers rubbing generate heat and that can be lovely.

I prefer natural fibers because I think they breathe better and keep me better regulated. And as someone that works outside year round in the Midwest, layers are what work. I have found that keeping my chest the warmest, it helps keep the rest of me warm as well.

Just don't sweat, or if you do, be down to the lowest layer possible. And when you go in, get down to the lowest layer to air out the top layers and to help regulate your body heat.

In my experience, you dress differently if your job requires a lot of moving vs a static job. Second one is way worse when it's really cold

Layers

Nothing is skin tight

Any exposed skin is going to be a problem

I drive a forklift so how ever cold it is outside I get an additional 8mph of wind-chill

So today is really going to suck as there's 15mph winds coming in, so in one direction I'm getting 23 mph worth of wind-chill and the other I'm getting 7

Edit: Also overlapping seams are pretty important as gaps can let air flow in when in motion

One thing that helped me more than I expected was an insulated face mask. They're usually marketed to hunters. A good one sits comfortably below glasses or safety goggles, and it stands just off your face except for the edge.

Adding this allowed me to be more comfortable in colder temperatures and strong wind with less layers overall.

I used to work for a big hardware company and we regularly sold heated jacket that just accepted tool batteries. For example our Milwaukee jackets just accepted the Milwaukee tool batteries. So when you're on the worksite you just swap out and recharge the batteries as needed with all of the other tool batteries. I got one of those jackets myself once and they are super nice. It could toggle between 3 different power levels depending on what you needed and the battery actually lasted a surprisingly long time.

As far as the rest of your body goes just layer up. Long wool (or goretex if you have the money for it,) socks, long underwear, thermal pants, boots, gloves, ski mask, and maybe an additional hat plus your coat hood. Of course you also want torso layers with the heated jacket but if you're using one of those then it will be doing most of the heavy lifting as far as keeping you warm goes. If you frequently get cold feet/hands then you can also add glove liners and an extra pair of socks or just toss some instant heat packs in your socks and gloves as needed (they normally last several hours).

Also when it comes to your inner layers avoid cotton like the plague. The saying in boyscouts was always "cotton kills" because even though cotton is insulating, it loses all of its insulating properties the moment it becomes even slightly damp and it will not dry on its own. When it gets wet, wearing cotton is worse than wearing nothing at all. I personally made that mistake once and I was literally better off once I pulled off my socks and just walked around with my bare feet in my boots. When it comes to fabric choice the ideal choice is wool because it's insulating and getting a little wet doesn't impact that too much. But if all you have are synthetic fabrics then go with those; they typically don't insulate as well but they still work better than cotton when they get wet. If you have the money and feel like splurging, goretex is a synthetic fabric that is supposed to be even better than wool; I've never gotten the opporitunity to try it out though so I can't say much there.

Under shirt, underwear, spandex thermal tops and bottoms(think under armor), wool or heated socks, insulated Thorogood boots, t-shirt, heated vest, work pants, work jacket, warm beanie, thinsulate leather or fleece gloves that I may have a hand warmer in.

With that I can work all day in Midwestern winter and compromise very little range of motion. Hand dexterity does take a tanking with the thinsulate gloves but they are warm enough to keep my fingers feeling things.

I often am outside for hours and then inside for hours; taking off the gloves, hat, jacket, and vest keeps me from overheating inside. The real game changer for me was the heated vest and the spandex thermals. I was working outside in the 30s and didn't need a jacket with the vest on low.

Have done that, but don't anymore.

My regular day was: Feet: boots over heavy socks over lighter socks

Legs: pants over thermals and sometime a layer of sweatpants in between

Main body: hooded canvas coat over heavy sweatshirt over long sleeve shirt over thermal shirt over T-shirt. alternating layers tucked into pant layers

Head: jacket hood over sweatshirt hood over heavy winter hat.

Hands: usually bare for the work I was doing, but when I could, I put them in some fantastic mittens my brother gave me that have been nicknamed "bear vaginas".

If I got too warm, I could shed upper layers pretty easily to regulate temp, but rarely did I ever need to do more than lose the coat and sweatshirt.

Disclaimer: I don't do that.

But as other have said, layers trap warm air better than 1 thick layer. This is the theory behind double glazed windows. Also why multiple thin blankets warm more than one thick one.

So long Johns, vest/light t, long sleeves T-shirt, sweater, and coat. Strip down or keep on as desired.

I used to have to walk 6km home late at night in -30 c or colder I would wear 2 pairs of socks with PJ pants under my jeans with a sweater and jacket. Also tight boxer briefs will keep your junk warm . I found loose ones would cause my junk to get really cold .

How do folks deal with needing to use their fingers for fine motor tasks outside in the cold mitigate the potential damage to nerves and shit?

If it's really cold I'll do 3-4 layers. Typically for my legs I'll do Long John's, then a pair of sweats, then my jeans.
For my torso I'll also use a Long John shirt, then a long sleeve sweatshirt, then a hoodie, then a Carhartt jacket. Also, always take a few extra pairs of socks, if you're feet get wet from sweat, they'll get very cold as soon as you slow down or take a break.

Underpants, shoes.

That’s it.

Pair of jeans, a T-shirt, and maybe put on a hoodie halfway through.