If you sleep with poison on, you don't wake up.
If you camp with poison on, you don't wake up, but the camp skill is removed at the tick.
Maybe by bug, maybe by design.

You are affected by:
Spell: 'curse' modifies save vs spell by 8 for 11 hours.
Spell: 'curse' modifies hit roll by -4 for 11 hours.
Skill: 'poison' modifies strength by -5 for 6 hours.
Spell: 'faerie fire' modifies armor class by 64 for 2 hours.
Skill: 'herbs' for 1 hours.
Skill: 'chill touch' modifies strength by -1 for 1 hours.
Skill: 'camp' for -1 hours.
You shiver and suffer.
Your poison mauls you.

<40%h 100%m 100%v forest trail 7596tnl (27.93%) 11 PM> aff
You are affected by:
Spell: 'curse' modifies save vs spell by 8 for 10 hours.
Spell: 'curse' modifies hit roll by -4 for 10 hours.
Skill: 'poison' modifies strength by -5 for 5 hours.
Spell: 'faerie fire' modifies armor class by 64 for 1 hours.
Skill: 'herbs' for 0 hours.
Skill: 'chill touch' modifies strength by -1 for 0 hours.

<40%h 100%m 100%v forest trail 7596tnl (27.93%) 11 PM> sleep
You're already sleeping.

n/t