Originally Posted by Hanson
What about just a space blanket when it gets down to 55-60? Is that enough, or is anything under 70-ish UQ weather?
The problem w/ space blankets is their mode of insulation. That is, they are not designed to hold heat in like conventional insulation (which prevents CONDUCTION of heat due to the nature of the material and CONVECTION of warm air due to the air pockets.).
Space Blankets on the other hand are designed to stop RADIATED heat from escaping and are REALLY bad at stopping CONDUCTED heat... so if you are in close contact with the pad its gonna sap the heat off of you just like you were pressed up against any other sheet of plastic exposed psudo-direcly to the cold air.
Space blankets have their place but I just don't think bottom insulation is it - maybe as part of a larger system but then we have condensation issues... so it'd have to be sandwiched in between other more conventional insulation to insure the temperature delta wasn't high enough to cause water droplets to form on it (yicky bathtub hammocking).
If you want to go light use a light-weight down UQ.
If you want to go cheap use wool blankets or foam pad (low compressibility) for these temps