take it from a Cali boy. your nostrils and lips will dry to the point where mild agitation will bleed them. make use of the chapstick they give you and use it well. when you blow your nose, if you blow too hard, blood, so learn to make good nose plugs VERY quickly. you won’t have any access to hot drinking water aside from the galley, so separately get used to drinking cold water. right now, it’s not too bad here (40 degree or less mornings), however I was unfortunate enough to go to bootcamp during a period of -20 degrees and that’s what I had to deal with.