Originally Posted by scum
I've been considering this as well. The wool sock just doesn't seem to quite slow it down enough. Really need something to insulate and allow a slow seep of warmth. I'm gonna have to see if I have enough reflectix left to try this...
Sorry I am late in replying to this, but I use a reflectix cozy with my Nalgene anytime the temps are below 30°F (as a native Floridian, I don't like to be cold
), and have used this trick down to roughly 20°. I have always had a warm water bottle when I got up in the morning. Never an issue.
Be sure that when you make your cozy out of reflectix that you use the appropriate tape, as some tapes are only rated to 140° (or less). Gorilla Tape is rated to 200°, and others are even higher, but more expensive. Check out the temperature rating before you act.
As for the poster who remarked on a "soft" misshapen bottle, you must see my post on page 22 that was really shocking of the effects on sub-standard plastics: The Amazing Shrinking Bottle