I do not use my wool layers to hike in when I am in the Sierra. I have two Ibex tops - given as gifts. These are my warmth layers - not hiking shirts. One problem I have with any clingy clothing, wool or any other fabric, are mosquitoes - they all bite through these. I use a very loose hiking shirt - actually the Columbia XL boys shirts with the bellows pockets. These keep the mosquitoes from biting. Maybe guys who have more body hair do not have this problem. I also hate DEET and prefer not to have to spray myself with chemicals.