help!

Yes, you can do this. No order needed. To continue doing them on a regular basis (if this looks like a problem) clue the doc in, and get orders for whatever is appropriate.

For the person who just "feels" off, you can do the fingerstick on your own.

It depends on the facility. Where I work, we have to have a physician's order for a non-diabetic patient. If the patient is diabetic, we are allowed a prn check of the patient's blood sugar. You should check your hospital's policy.

nu uh! not at my facility, if a patient is starting to get diaphoretic and such, it is good nursing judgment to check that sugar, one of the things the doc will ask me is if I checked the sugar.

Out of interest, what would be the rationale of a facility for not checking someones blood glucose level if you are concerned?