Excuse me if posted elsewhere or not, but do these things actually work? Any articles, reviews, research?
A study by supported by Polarwrap allegedly scientific methods followed http://www.polarwrap.com/lab.htm
Here is what their promotion says, accurate or not about the mechanisim and the effectiveness
"The Patent Pending mask features a QXTEC module that is made of desiccant coated plastic. The desiccant grabs the moisture from the air, forcing a phase change from vapor to liquid. This phase change releases heat and is added to the natural heat of exhalation, warming the plastic. This warmth is transferred to the air as it is inhaled: creating a warm “breath of sunshine.”
The heat exchanger is up to 80% efficient, meaning that at 0 Degrees, your inhaled breath can be warmed to over 75 Degrees before it enters your body! Efficiencies vary with respiratory rates and lung capacity.
It functions to reduce dehydration and increase lung capacity in extremely cold conditions. By warming cold air as you inhale, the fin-enabled Heat Exchanger helps maintain normal blood flow levels, which keeps more warmth around body extremities like your hands and feet."