Think violent, uncontrollable shivering that calms down to numbness, with an odd warmth in your torso... like a flame where your heart used to be. If you have joint problems like I do, the shivering hurts like hell.
I drove an old VW bug on a three hour journey in windy -15 degree weather once. By the time I reached my destination I had to start a fire to warm myself... I couldn't manipulate anything with my fingers, whatever I touched sent sharp pains radiating from the point of contact throughout my body. I had a warm feeling in my torso, but my extremities were numb, except the pain from my feet and hands. It took all the "mental force" I could muster to get that fire lit... I literally had to focus my concentration in order to make my own body move the ways it had to move.
Very strange sensation.
Once lit, the fire warming me hurt like hell. It took hours before I could function normally enough to get myself into the trailer I had on site, and light the heater. It took a few days to get over it, entirely.
One of my neighbors a few years ago liked to get naked when she'd drink whiskey. She liked to wander, too.
About three years ago, in the middle of January she got black-out drunk and wandered until she collapsed in the snow, naked as a jaybird, about 150 yards from my house. She's lucky she was found when she was, she'd been out there about two hours. When I asked her about it referencing my sensations years before, she said she couldn't remember a thing.
I suspect she was a bit embarrassed and felt uneasy talking about it.