Don't wash too often, it'll hasten shedding and fading. The less you remove and replace the better for longevity.

I'd be confident going to hospital with the full cap on. But I'd make sure it was really anchored down strong - none of those wimpy 2 day hold glues, or tapes that melt away into the piece in a few days. It would be Duotac back to back so the strong hold side is both on the piece and my skin. This has the stregth of blue tapes but doesn't go off all gooey like those do after a couple of days.

Two to three weeks with absolutely no movement for me with this set up. If I use just one piece of tape on its own it lasts about a week. Only down side of the back to back tape arrangement is that it is a little bulky underneath so you might get busted when those naughty nurses start running their hands through your hair.