Originally Posted by wisenber
If you were also in a sleeping bag and not just a TQ that might work. On it's own, a space blanket with a piece of nylon probably won't get you 20 degrees of insulation.
Also, if you're a condensator/sweater like I am, you'll probably be wet on the underneath side in the morning. Another thing, the space blankets tear pretty easily.
I've found in the warmer temps(50 and up) that a large sized windshield reflector works for me. They are cheap, light and pack down pretty well.