Is 12 hour shifts safe

This has been a debate for at least the last century. How many hours can a caregiver work within their capacity before we see a degradation in performance to unacceptable levels? A lot of the answer depends on the job. NA's, who operate with a lot of backup and are rarely invovled in life-endangering procedures are probably less of an issue at 12 hours than a neurosurgeon in surgery. And in fact, lengthy surgeries nowadays are scheduled with operating teams, to ensure no one team becomes over-fatigued. A lot of the answer also depends on the person. How sharp are you after 12 hours? :}