I remember one nurse, who would tend to find a quiet med room to rest in every night, was given the responsibility of orienting a new nurse to our floor. Well, when 3 rolled, his usual nap time, his head would bobble and his speech would slow down; this is when having a sleepy time break every shift works to one's disadvantage! Nothing more embarrassing than looking like a drunkard at 3 am!
He was however, the very best nurse to hunt down for a tough IV start. You know the one's where you end up starting one on the shoulder or upper arm. So I never complained about his taking naps. A resource like that is priceless!
I can remember thinking if I dared to sleep in the break room when I did night; someone would soon be vigorously tapping me on the shoulder and barking: "Callacode, Callacode -- wake up, time to give your report." Or heaven forbid, "Your patient is coding, why are you sleeping!"
Some countries like Canada, for example allow their staff time to rest at night, even supplying a resting room. I wish some nurses could realize that sleeping on night shift is not always so particularly bad, especially when the nurse taking a cat-nap has let other nurses know their status.