Make sure you have appropriate medical insurance during your time spent abroad. You do not want to be surprised by having to pay for unforeseen medical issues.
Students coming from EU member states and the countries of the European Economic Area should have a European Health Insurance Card which can be used to cover any necessary medical treatment due to either an accident or illness within the EEA - European Economic Area (E 128 form, E 111 form or E-card. The document type depends on the authorised insurance agency of the country of origin).
If your stay exceeds a period of three months, a residential permit is required.