The Patagonia Micro D Snap-T Fleece Jacket layers under a shell without adding bulk, and at 4. 6 ounces it disappears in the diaper bag until the temperature drops. The fixed hood and hip length close the gaps at collar and waist that matter most when a baby can't tell anyone they're cold. What Our Gearhead(R) Experts Are Saying:"When it's time to bundle up for the stroller walk or a quick errand in the cold, this one goes on first. The snap-flap chest pocket and handwarmers mean there's a place for everything small hands might need nearby."