My son (11) and I spent an hour or so outside during our "artic blast" that came through the area, testing our newly acquired Montbell UL SS #0 (zero degree F down) sleeping bags. The temperature was ~ 2 degrees F with wind gusts in the 20-30's. We both were wearing the following:

Feet: double smartwool hiker socks
Legs: thin baselayer, 200 wt fleece pant
Torso: thin baselayer, 260 wt merino top, micropuff pullovers
Head: mid weight beanies
Sleep pads: regular length Therm-a-rest Prolite 4 plus two layers of Gossamer Gear Evazote 3/8" thinlights

Overall, we were completely warm (I could have easily not worn the micropuff) and with exception of our noses, did not feel the wind gusts.

In conclusion, these bags rock! They are very warm, windproof, and for less than 3 pounds, not bad on weight. I think I could take these bags to at least -10 to -15F with the clothing system we had on.

Here we are bundled up:

Edited by brianjbarnes on 12/22/2008 16:38:07 MST.

Let us know how they do over a complete night at those temps.

Hi Brian,
Good stuff.
FWIW, my winter camping buddy has one and has taken his down to -6F (-21C) with just a base layer on...sleeping on a Full Length DM7. We actually had temps hit 0F (-18C) last night when we were out...no problems. You made some good purchases!

And for those interested, my trusty Versalite endured the same beatings, with baselayer and VBL, used on a DM7 short.

Let us know how low you go!