I used Reflectix (which is one of the insulations that looks like bubble wrap covered in aluminum foil) to insulate an un-insulated room in an un-insulated garage in South Dakota one winter. It worked very well and is fire rated so no safety concerns with having it out in the open.
It is also easy to take down and use again, which I have done several times since I orginally bought it. In fact I just got it out again to drape off part of our basement that we've moved into during some remodeling. Here is a picture of that room I originally purchased it for.

-----
Current snakes:
0.0.1 Gonyosoma oxycephala - Java locale (green)
1.2 Gonyosoma oxycephala - Jave local (green)
2.2 Gonyosoma janseni - Seleyar locale (all black)
1.2 Gonyosoma janseni - Celebes locale (Black & Tan)