Ferðafélag Íslands Mountain Huts

You have to bring your own sleeping bag as neither sleeping bags nor blankets are provided. The huts are warm, so the sleeping bag does not have to be of arctic quality.
In the bigger huts you can expect both running water and water toilets but in some of the smaller ones, you will have to fetch water to a nearby stream and use a latrine/outhouse.
Ferðafélag Íslands Mountain Huts in Landmannalaugar have a shower.

Please note that it is not possible to buy meals in most of the Icelandic huts; you will need to bring and carry your own food.