Hot Chillys La Montana women's line is aptly named, it is truly our king of the mountain for warmth. The fabric of these ladies' thermal long johns consists of brushed, micro-denier polyester fleece for lighter weight and greater strength and durability. But to ensure this armor-plating of warmth doesn't interfere with your active endeavors, we've placed stretch panels in the gusset areas for added maneuverability.a unique product for those demanding the warmest possible undergarment for winter or mountain sports, these heavyweight base layer pants are guaranteed to keep you warm, dry and comfortable so you can have some fun!