I did work night too; From 23:00 till 7:00 am... cleaning machinery in a chicken slaughterhouse.... it was very painful job, not that it was difficult, but cleaning blood, chicken fat and guts, it is, well, not very good for the self-esteem and the need for self improvement.
Anyway, the job was shit but if you can have enough rest between the two shifts, physically it is not too bad; Normally I was sleeping 5-6 hours when I came back and was active around noon till 20:00 where I was taking another little nap if I was feeling tired again.
Nightshifts aren't the ideal but definitely manageable, as long as you have enough time to rest in between and to do something so you don't have the impression to be a zombie.