First aid for concussion
If you think someone may have a concussion, use the following steps:
Check to make sure the scene is safe.
Check for loss of consciousness.
If the person is unconscious, check their ABC (airway, breathing, circulation)
Do not move the person unless absolutely necessary.
Check the person’s mental awareness.
Check the person’s eyes.
Watch for vomiting.
Keep the person awake for a period of time to see if their condition gets worse.
Be aware that complaints can subside only to appear later on and be worse.
Be aware that children can become worse very quickly.
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/head-injuries-and-concussion#first-aid-for-concussion