Not so much - Marmot Isotherm Hoody - Mens

This from Polartec: Polartec ® Alpha ® was originally developed for the U.S. Special Forces when they required a more advanced insulating material in their combat uniforms. This fabric is a new technology with active insulation that regulates core body temperatures during both dynamic and static activities. This latest advancement in adaptable breathability helps eliminate the need of shedding or adding layers while on the move.
Sitting inside in a cold winter Chicago day, this hoody was not as warm as a light weight fleece. Might work well outside being more active, but Polartec says warm, either way.

This review was written in the old system and had content requirements that are different than reviews written today.