HI. Your questions sheds light on something that happened to me a few years ago. I was leading an ice pitch. My partner was belaying on the ground. Before I started climbing, he was complaining about cold hands. Sometime during my pitch, his Screaming Barfies became so bad–the pain and nausea became so bad–that he passed our cold. I had no idea. I got to the top of the pitch and built an anchor. When I turned around to look down and confirm that he should lower me, I saw him lying in the snow, and another climber, a stranger, who happened to be there, belaying me. The other climber, wisely, I would say, didn’t say anything when my partner passed out–he just quickly stepped over and put me on belay. Crazy, lucky, insane, whatever. It’s a true story.
My partner later shared the story on UKC forums, and if I remember correctly, at least one other person had a first hand experience of somebody passing out from the Screaming Barfies.
So I imagine that some part of the physical response to having very cold hands that re-warm is, or can be, a rapid drop in blood pressure that, infrequently but possibly, results in a loss of consciousness. I don’t think the flow of blood into previously constricted vessels in the hands is enough to explain the dramatic drop in blood pressure. There must be a neurological component as well, perhaps a response to the pain, or some kind of systematic, or larger scale (not just the hands) vasodilatory response.
Maybe somebody else has some other ideas/firm knowledge?
I think this is good to know about; for example, climbers might remind themselves to clip into an anchor or ice screw o other protection if they have really bad Screaming Barfies.
For me, I find it’s worse when I have been inactive (belaying) and then climb.
Once it happens during the day, it rarely happens again.
Keeping everything warm–heads, neck, feet, wrists, and so on, as trying not to grip tools to hard, and quickly changing out of cold/wet gloves, seems to help prevent it.
Even the greats get Screaming Barfies; there is a great video of Dani Arnold and David Lama climing in Alaska where Dani Arnold gets an attack.
Here in German-speaking Switzerland it’s called “Kuhenagel” or “cow nails” becasue, I guess, your hands feel like cow’s feet?
Anyway, Screaming Barfies = possible rapid drop in blood pressure. Good to know.