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 for:
Severe difficulty breathing, blue or grey lips, or long breathing pauses
A seizure, collapse, or difficulty waking
Sudden weakness, inability to walk, or loss of bladder or bowel control
A severe headache with repeated vomiting or marked drowsiness
A serious allergic reaction during or after an infusion
Routine concerns, such as gradually worsening stiffness or hearing, are usually handled through the specialist team rather than an emergency department.
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
Contact the specialist team promptly for a new change in walking, strength, coordination, bladder control, hearing, vision, sleep, breathing, or development.
Increasing snoring, repeated pauses in breathing, frequent falls, persistent pain, or reduced ability to move a joint also need assessment.
A fever during this period often needs urgent assessment even if the child otherwise seems well.
The article also says
During transplant recovery, follow the transplant team’s instructions about fever, exposure to infection, vomiting, diarrhoea, rashes, or missed medicines.
Every sign above is quoted from the sofidex article on Hurler disease. If you are not sure, err upward — it is always reasonable to be checked.