Light Sleeping

This proficiency lets the character receive the benefits of a full night's rest from a one-hour nap. The character must make a proficiency check before going to sleep. If the check succeeds, the character awakens in an hour, fully refreshed; he recovers the same amount of lost hit points as if he'd rested for eight hours. If the check fails, he remains asleep, awakening as usual. He may use this proficiency only once per week, regardless of whether it fails or succeeds.

This proficiency is not effective for purposes of spell memorization.

[Complete Barbarian's Handbook]