A Norwegian visiting Brussels for a conference would be treated the same as a Belgian citizen should they break their leg. Overall, it’s a great program that offers Europeans a lot of flexibility and peace of mind.
32 countries participate in the European Health Insurance Card program. That’s 28 member states of the European Union, 4 member states of the European Free Trade Association, and Switzerland.
You do not have to be an EU citizen to use the EHIC. If you are a legal resident and covered by European social security you are also covered by the EHIC in most countries. However, even if you successfully receive the EHIC as a legal resident expat, you cannot use it in Denmark, Iceland, Liechtenstein, Norway, and Switzerland.