Can I bring some snacks or water during the NCLEX?

I think it depends on your testing center. Where I tested it was like visiting a maximum security prison and I practically got a cavity search. The staff made it less traumatic but that part of the experience was a huge mindmuck for me, like very intense. You can probably call your center ahead of time to mentally prepare.

Absolutely! Bring a high protein high fat snack to munch on when you start to get tired & restless. A stretch break / snack & water break / toilet break does the body good and helps you re-focus. You just have to leave the food/drink ON TOP of the lockers or another designated area as you cannot get INTO your locker once you start the test.

I don't think so. I had to remove my headband and jacket.