When I was still into caving and rappelling, we used to do long survey and mapping trips into caves that had long water-filled passages. To stay warm while swimming, wading or diving under submerged rocks into the next passage, in the 60 to 65 degree F water, we often wore diving suit tops or thick woolen sweaters. The woolen sweaters performed admirably, even when soaking wet.

You'd have to wring the sweater out and stow it for the long crawl out of the cave, since these caves were in the southeast US. We were lucky we had such intelligent and athletic girls in our caving club, and especially on those wet survey trips. I still have a terrible weakness for girls in sweaters.  But we were all friends then, and it was just one of those things. I have good memories of all the hiking and campfires and adventures we had. But that was back in college and afterward. Even with all my responsibilities now, I'm glad I had the time for such madness in my twenties.

Wool is certainly a miracle fabric.