Garments may include targeted vent or heat retention zones including openings or heat insulation areas in the fabric of various different sizes. The locations and sizes of these openings or heat insulation areas, at least in part, may be determined based on a thermal profile of a body from which the garment is designed. For example, openings or heat insulation areas of a larger size may be provided in the garment at locations where the body typically releases a large amount of heat, and openings or heat insulation areas of smaller sizes may be provided at other locations, e.g., where the body releases less heat. Several thermal profiles may be collected and used to develop a collection of opening patterns, e.g., corresponding to specific body characteristics, body types, and / or ultimate end uses for the garment. Custom patterns may be determined and used in garments specially designed for individual users.