Sleeping is a very complicated process. There is a 1/2hr "technical lesson" about that.
Contrary to what people think, you will not freeze and die at night. Your brain will wake you up and let you know something is up.
Before sleep, it is strongly suggested that you warm up your core temperature. There are a couple of Jaccuzzis and a Sauna (all outside) that you have to warm up in before going to bed. The beds have plywood and mattress on them. You also are given a -30C sleeping bag and an inner shell that you get in to. Then you have to bundle up and only leave the mouth, nose area exposed. Its pretty crazy, and a bit scary. It took us a couple of minutes to zip in and seal up the bags. If you have to use the bathroom at night, the process starts all over. Some rooms are located on the other side of the complex of the bathrooms (about 100 meters away) and the quickest way is by outside.
Again, worth to try once in your life. We saw some families (with kids) that were staying for a couple of nights .... nutts.