I experienced a genuine panic attack during my Fundamental Bushcraft course at Woodlore a couple of weeks ago.
We were sleeping in leaf litter shelters, I had gone to sleep with no problems whatsoever.
However, I woke at about 1.30, as those of you who have slept in this type of shelter will know they have very good sound insulting properties and are very, very dark. I think it was this silence and total darkness
that got me, but I just had to get out of that shelter, the panic was simply overwhelming.
I spent the rest of the night in my tent and declined to use the shelter again on the following night.
As an aside, getting back to my tent proved to be something of an adventure all of its own, being on unfamiliar ground, with a rolling patchy fog to add to the fun.
I think they call them "character building experiences".
Dave