What should I pack?

you really don't need much of anything.
just bring an extra pair of underwear, a pair of fuzzy socks to keep your feet warm, and a hair brush/hair tie.
and maybe bring a tooth brush and tooth paste. typically the do provide it but just in case.
and bring deodorant.
thats really all you are gonna need.
you'll be taking your clothes off shortly after you arrive so they won't get dirty so you can just put them back on the next day.
most hospitals also provide cable tv so there's your entertainment.