The antarctic suit is a multi layer system that ends with the main parka coat, pants and bunny boots.
I started using poly-underwear a size bigger than I need so I don’t get the the closed in feeling.
I am on a Search and Rescue Team that goes no matter what. We do travel as far as we can by snowmobiles, tracked vehicle ect. When the trail can no longer be driven upon, we snowshoe. You start to heat up you unzip or remove layers of clothing. Pretty simple process really.
Best Regards, Rick