So, here is the answer I got from my insurer (IAK)'s customer support line. (I assume it is true for other insurers as well, typically, but don't take my word for it and ask.)
- By default, your health care coverage does not include medical care which needs to be administered out of the Netherlands.
- You can purchase a pretty cheap addendum for such coverage.
- There are two tiers of coverage w.r.t. geographical area: EU-only, or entire-world.
- A month's worth of coverage in the entire world cost something like 3.84 EUR
- You can pay extra for: Sporting activity insurance; "Cancel all my credit cards since my wallet was stolen" service, and car ride coverage abroad.
I'm not sure how good this coverage addendum actually is, since I haven't gotten the full text of the policy and it'll probably be in Dutch, but that's basically that.
Also, many (most? all?) Israeli health care providers / health insurers don't offer a similar arrangement unless you're departing to and returning from Israel.