terrymorse No, didn't do an "acclimation night" ... might have helped, and retrospective reading certainly advises it. I'm likely pre-disposed to it based on past experiences (headaches, confusion at Targhee), but when younger, it was never this acute. BTW, readers, don't bother too much with the 02-in-a-can; if you're really sick, that provides about 15 seconds of relief, then gone again. Will be in New Zealand in January - I'm taking meds with me.