The 2010 models are out, and Marmot really brought their A-game! It would appear that when converting to ºF, Marmot still uses * 9/5 part, but their researchers have come up with a way to eliminate the +32. For example, the new ratings for the Helium:
* Comfort
-4.3F / -2.4C
* Lower Limit
-15.7F / -8.7C
* Extreme
-48.6F / -27C
Forget Western Mountaineering and Feathered Friends - I'm getting a Helium! Under 2lb ...