Got this jacket and wore for first time this week. 55* and cold north wind in Northern Michigan. Ran it on medium heat and was plenty warm. Size runs small. I ordered Med (which would normally fit great, I am size 10/12, c/d cup) returned for a large. Chest runs tight. Could get med zipped half way up. You want it to be snug, so large is comfortable. If ordered again I would go extra large to fit mid weight shirt under it. Large can fit thin turtle neck, Under Armor type shirt. It is light weight enough that it fits great under heavy leather jacket for extra warmth and protection. Side stretch panels are great. Ordered "wine" color. Closer to red than wine. Great product!