I don't know if you wanted non-experts to reply, but because I too have to climb solo a lot, here's an interesting experience that occurred recently that's on point with this HSS and a few tips from an expert.
Recently, at the SERA regional meeting of the NSS(Nat'l Speleological Society) in which cavers meet to compare, compete and explore, there was a live expedition in a cave in which there was an emergency rescue on rope of two fairly experienced cavers.
The first caver got stuck ascending on the rope, for some reason(I don't remember exactly why) and when his friend tried to ascend up behind him to help, he jammed his top ascender underneath him in order to get closer and he also became immobilized. The cave was difficult and took rescue workers several hours to get to the two victims.
After hours on the rope they both began to experience HSS and one was unconcious upon extraction.
Very, very fortunately, there was a doctor present who was specifically familiar with HSS and its effect on the blood and circulatory system, such that any other doctor may not have known exactly what to do.
Here's why, this particular doctor instructed them not to remove the harnesses until after a certain type of injection was given and had time to work in the circulatory system, because he explained that the blood becomes very acidic and pools in the lower extremities and if the harnesses would have been released without this medicine being administered first, the acidic blood would have slammed against theirs hearts and killed them. Very fortunately they lived.
This story came from Bruce Smith, author of On Rope, when I was in one of his classes back in June, to illustrate the point that Rescue personnel must know and be trained specially for climbers. And that climbers should be aware to keep moving in some way no matter what.
Bruce Smith shared several points for us climbers:
1) Never climb w/o a way of communicating for help.
2) Never remove the harness of a victim who has been suspended for any length of time immobilized.
3) Keep moving in your harness if stuck.
4) Carry a prussik loop or foot loop in order to stand up periodically to keep the blood flowing.
5) Never jam your ascender under an object or always leave space under any object while ascending in order to be able to changeover and descend if needed.
Just wanted to share this real life episode with you guys.
Safe climbin.
Charlie Brown.