Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency care for worsening balance together with severe headache, repeated vomiting, new weakness, a seizure, confusion, unusual sleepiness, fever with neck stiffness, or inability to walk safely.
And for anyone, someone who:
After urgent causes have been addressed, follow-up helps track recovery and decide whether further testing or rehabilitation is needed.
The clinician may repeat the neurological examination and ask about walking, falls, speech, school or work, headaches, and daily activities.
Contact the treating clinician sooner if recovery stops, symptoms return, or new problems appear.
Persistent or unexplained ataxia may require review by a neurologist.
And for anyone, someone who:
Keep scheduled follow-up appointments even when symptoms are improving.
These are not routine follow-up concerns.
The article also says
During recovery, follow the care team’s advice about returning to school, work, driving, sports, and unsupervised activity.
A gradual return may be needed when balance or fatigue remains a problem.
Every sign above is quoted from the sofidex article on Acute cerebellar ataxia. If you are not sure, err upward — it is always reasonable to be checked.