Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Seek emergency help if your baby:
Is very difficult to wake or does not respond normally
Has a seizure
Has trouble breathing or develops rapid, deep breathing
Looks blue, gray, or extremely pale
Has severe dehydration with very little urine
Has repeated vomiting with worsening drowsiness
Has a very high glucose reading plus ketones, when home testing is prescribed
Do not delay emergency care while trying to correct the glucose with extra water, altered formula, or an unplanned insulin dose.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
In hospital, tell the bedside team promptly if you notice a major change in feeding, alertness, breathing, urine output, or the number of wet diapers.
These signs may reflect glucose changes or another newborn problem.
After discharge, contact your baby's healthcare service the same day if your baby has repeated vomiting, feeds much less than usual, is unusually sleepy, has noticeably fewer wet diapers, or has glucose readings outside the home care plan.
A fever in a baby younger than 3 months also needs prompt medical assessment.
Every sign above is quoted from the sofidex article on Hyperglycemia - infants. If you are not sure, err upward — it is always reasonable to be checked.