If you are not registered with a doctor but need to see one, you can receive emergency treatment from a surgery for 14 days. After 14 days you will need to register as a temporary patient or permanent patient.
You can request a Temporary Resident Form from your surgery. You can register as a temporary patient if you are in the area for longer than 24 hours but less than three months.
For more information please visit NHS: How to register with a GP surgery.