I've never had this problem, and I run in wool long-johns all winter in Boston. I'm not sure how you get more cold in one sort of 100% merino wool underwear than another. You know they make them in different weights?
Anyway, I run, bike, snowboard, and just throw them on to walk the dogs all winter, I use both Icebreaker and Smartwool, they are both great, they never smell bad and have held up under years of abuse. The only difference is that the Icebreaker can't be dried in the machine.
Originally Posted by Michael Ay329
I am happy with the following Filson Long Johns:http://www.filson.com/family/index.j..._Underwear_txt
It can be machine washed cold and line dried...useful out in the field too
I have also tried the SmartWool long johns. I found the SmartWool to be a bit softer but WAY INFERIOR in keeping me warm. When the Filson product got wet from my excessive sweat...I still stayed warm. When the SmartWool product got wet...I started to suffer chills from the cold and ended my excursions in the cold quickly in order to dry off and put on the Filson product instead