This has to be the warmest shirt I have ever owned - in fact, my husband and I own several. He is a fishing guide and never gets a chill while fishing in winter. If you need a warm layer - this is the shirt to get. I have both the crewneck and henley style. You can't go wrong with this shirt!!
I work outside in upstate New York all year round. I need comfortable, durable, warm clothes. I recently bought three crew neck river driver's shirts because 1-I love the simple styling; 2-the 2-layer construction of wool and cotton on the outside and cotton inside. They are very warm and very comfortable; perfect for layering under outerwear. I think the colors are very handsome - I might work in the woods a lot, but I still like my clothes to look decent. I am very happy with these shirts.