The character touched is able to stay awake all night on watch. For the duration of the spell they have proficiency in perception rolls. If they all ready have proficiency in this skill, the bonus is doubled. Moreover, the character does not suffer the effect of fatigue and does not gain an exhaustion point.  

The character obtains the benefits of a short rest, but not the benefits of a long rest.  You cannot cast this spell more than two days in a row, if you try to cast the spell a third time within 48 hours the recipient immediately gains two points of exhaustion.