We'd been driving missionaries in our zone to the temple open house for a couple of weeks, leaving very early and getting home very late. We frequently drove on the freeways at ~100 MPH so that wasn't that unusual. This late night, my companion was sleeping and I was driving. My eyes were heavy and I nodded off. I don't know if my eyes were shut for half a second or several seconds but at some point I awoke with a start and HUGE rush of adrenaline. I may not have been THAT close to death, but it was certainly a situation I don't want to repeat.