Vented garment

An upper body garment comprising:

• a garment layer comprising a first surface and an opposite second surface, wherein the first surface of the garment layer is configured to face toward a body surface of a wearer when the upper body garment is worn;
• and
• at least one vented-insulation section affixed to a portion of the garment layer configured to align with a chest area of the wearer when the upper body garment is in an as-worn configuration, the at least one vented-insulation section comprising:
• a first woven or knit layer;
• and
• a second woven or knit layer,
• wherein the first woven or knit layer and the second woven or knit layer of the at least one vented-insulation section each comprise an interior surface and an exterior surface, and wherein the exterior surface of one of the first woven or knit layer or the second woven or knit layer is configured to face toward the opposite second surface of the garment layer when the at least one vented-insulation section is affixed to the garment layer,
• wherein the first woven or knit layer and the second woven or knit layer are joined to each other at a plurality of seams, wherein each seam of the plurality of seams comprises a seam width between a first seam edge and a second seam edge, wherein the plurality of seams define two or more chambers between the first woven or knit layer and the second woven or knit layer,
• wherein the two or more chambers between the first woven or knit layer and the second woven or knit layer contains a thermally-insulating fill material within the two or more chambers, and
• wherein at least one seam of the plurality of seams comprises one or more openings, the one or more openings extending through the first woven or knit layer and through the second woven or knit layer of the at least one seam of the plurality of seams.