Yes, but the increase in warmth is not that noticeable.
While a duvet cover can add an extra layer of insulation, it may not significantly increase the warmth of a comforter. Duvet covers primarily serve to protect the comforter from dust and stains while adding a decorative touch to the bedding. While our silk duvet covers provide some thermal regulation and protection against skin abrasions, they should not be relied upon solely for warmth. It is recommended to consider other options, such as layering additional blankets or choosing a thicker comforter for added warmth.