All around Iceland we have these rescue shelters. The shelters were mostly built by the Icelandic volunteer search and rescue organizations in the early half of the last century. They are placed by remote hiking routes, high mountain roads, the coastline or generally anywhere people are most likely to get themselves into trouble. Each of these has a bunch of blankets, dried food, a vhf radio and usually some cooking or heating equipment.
Over the last century they saved many lives, but their importance is changing. With modern mobile phone coverage and better roads, many of these have lost their importance. However there are several huts in areas where people hike or by mountain passes without mobile reception that still remain important. These can be quite modern and well maintained.
I would say that this hut in the picture by Óli Már has lost its importance and I would not count on it being well maintained. It is only about half an hours drive from downtown Reykjavík today.
If you come across one of these huts keep in mind that they are life saving emergency huts, only intended for emergency use. Do not spend the night in them if it is not an emergency. They might only be checked upon once a year, so if you leave a door or window not properly closed, the hut may be ruined by weather.
For information about safe travel in Iceland check out the Icelandic Search and Rescue Service’s recently launced Safe Travel website.