You'll need to take:
Something to wear
Something to keep you dry
Something to keep you warm
A sleeping bag
something to sleep on for warmth and comfort
Somethng to sleep in, tent, bivvy, bothy etc
Something to eat
someting to warm it in/eat it our of
Something to warm it with
something to eat it with
something to drink
something to drink it from
Something to carry your gear in
A map and compass and the knowledge to use them
Something to patch yourself up with?