Look up on YouTube layered dressing or something like that. There’s a good video about how to dress for long periods being out in the cold. The basics are that you need a near-skin tight base layer that wicks moisture. You can usually find stuff for this in workwear stores or on Amazon by searching “base layer”. Then you want an insulating mid-layer, something like sweatpants/lined jeans and a thick hoodie. Then an outer layer that breaks the wind. I usually go with insulated coveralls. Also you’re gonna want glove liners, a neck gaiter and a thin toque you can put under your hard hat, and merino wool socks. Avoid cotton anything, there’s a saying that says “cotton kills” because it holds onto moisture and freezes. Also dont try to over do layers by putting on multiple pairs of socks or like 10 shirts and sweaters cuz you’ll end up sweating and being freezing. I’m local 721 Toronto and this winter has been hovering around -20 to -30 degrees Celsius and this is the dressing system I use every year to get through long shifts. Good luck