Sometime in the early 1990's.
It was winter, and I was camped in a high, cold place in the Oregon Cascades. The temperature that night was 17 degrees, by the little thermometer I carried on the zipper of my parka. I was having a hard time staying warm, and I kept waking up, because I was cold. I think the repeated transitions between waking and sleeping had something to do with this...
I woke, sat up in the tent, and rearranged my sleeping bag, and the frost liner above me. I scrunched back down into the bag, pulled it over my head, and rolled over on to my side. And I kept on rolling, oddly enough. I rolled right through the wall of the tent and outside to the snow-encrusted ground, where I bounced twice, lightly, in the cold dark air. I bounced and floated, as if I only weighed an ounce. when I finally came to rest, I sat up, and I was just sitting there on the snow. But I could no longer feel temperature in any way. I wasn't cold or warm, I just didn't feel anything like that.
All other sensations were perfectly intact. I could see the bright, hard stars above me, and I could see everything around me, in the dim moonlight. Instantly, I thought "up." I don't why I thought that, but my body (whatever it was in that moment) shot straight up. I went up and up and up, and I seemed to be passing through dark gray layers of .. Something. As I went higher, I felt more resistance with each layer I passed through. Finally, I hit something and bounced down.
I woke up in my tent, feeling cold.