When I had to live under evacuation after the earthquake, I could not get hold of blankets easily so I made simple bedding out of newspapaer and a plastic refuse bag. The method is simple : you crumple newspapaer and stuff it inside the plastic bag. When I put my feet inside, the layers of air trapped inside prevented heat from dissipating, so I could keep quite warm. This was much better than nothing on a cold winter`s night.
(Male,aged 15,Higashinada Ward)

When we were struck by the great earthquake, I escaped in my pajamas. It was a could day so I was shivering a lot.
Even when we got to the evacuation shelter, there was nothing to cover my body, such as a blanket.
What they had there were just big black refuse sacks. Having no choice , I wrapped the plastic sack around my body. It was quite warm, I remember, and a relief to me.
(Female, aged 60,Nagata Ward)

Fire Deperment Advice
In order to combat to cold, there are other means than these mentioned above. Cardboard boxes folded flat and laid on the floor will keep you much warmer than you think. Also,you can crumple up newspapers and crease them, then smooth them out and put them in between your underwear and outer clothing. This creates a layer of air that insulater your body from the cold.
Soon after the earthquake, many people had fled from their homes wearing just the clothes they were in at the time, so there were many only wearing pajamas.