Grayson found that a heavy layer on his legs, such as these Eddie Bauer Primaloft Igniter insulated pants ($149), helped him regulate his upper body temperature well because the lower body isn’t quite as sensitive to the temperature swings that are common at Base Camp.
They’re lightly but warmly insulated with 100-gram Primaloft, a synthetic insulation that remains one of the best synthetic fills because of its softness and water-repellency. The Igniters have a shell made from nylon that is treated with water proofing to keep you dry. They have two side pockets, side zippers for easy on-off, and articulated knees for good range of motion. And they're darn comfortable.
The Alternate: Similar to the Igniters is the Mountain Hardwear Compressor Pant ($160). These are also a synthetic-fill insulated pant, using Mountain Hardwear’s proprietary Thermic Micro insulation. A ripstop nylon shell treated for water-repellency, adjustable waist, and full side zips complete the picture.