When I was 19, my parents and I climbed a mountain in western Washington. It was mid-summer, but a lot of the mountain (especially near the top) was covered by snow fields. My dad was well-read and had a bit of mountain climbing experience from his college days, and he knew that you could quickly/efficiently descend from a summit like this by glissading:
The catch is that you need a way to control your descent so you don’t slam into the rocks at the bottom of a snowfield. Properly outfitted climbers have an ice axe with them, but since it was a bit of an afterthought for us, and my parents were, um, budget-conscious, we just grabbed suitably sized sticks from the forest before we ascended above the timberline.
After summitting, we began our descent. When we got to our first snowfield that was steep enough for glissading, we took a shot at it. And very quickly, we were out of control. It was a warm day, and the snow was kind of sloppy and quickly formed a sort of raft under us, making it extremely difficult to punch our sticks deeply enough to reach firm snowpack and provide a useful braking effort. My mom was next to me, but was getting bounced around a bit and couldn’t even get into a good position to jam her stick into the snow. I was getting bounced around too, all the while conscious that we were hauling ass toward the bottom of the snowfield, and probably serious injuries if we couldn’t get our speed under control. I managed to get over to my mom so that she could grab onto my leg, and then worked my body over to the edge of our snow raft to where I could jam my stick into more solid snow pack and start slowing us down. It took a long time of jamming that damn stick into the snow as hard as I could before I got us stopped; my arms and abs were seriously sore the next day.
I’m not always so on top of things. I learned how to drive in the '80s using rear-wheel-drive cars, so I was very familiar with how to control a rear-wheel skid in slippery conditions. But when it happened just a few years ago at something close to highway speed, my brain locked up, just too freaked out to accept what was happening until the skid was too far gone to recover. The resulting crash totaled my car; somehow I walked away without any physical injuries, but I was stuck with PTSD for a few years after.