The frost on me is from breathing. Temperature was about 5 degrees Fahrenheit but it was quite comfortable while riding. I wear neoprene tights, lightweight wool undershirt and an Ibex wool bicycling jacket, which was unzipped most of the time to keep from overheating. I wear a light wool beanie and neck gaiter. Eveything above the waist is merino wool. It is soft and warm and it keeps you warm even when it is wet from perspiration.