Great thermal.  Not too thick, but warm.

I often have to get a large in long sleeves due to my long arms/broad shoulders, but I took a chance and ordered the medium and the sleeves are perfect.

This is about as think as two cotton tee shirts, but it is much softer and feels great.  So far, I have washed/dried it three times and it has held up perfectly.  I expect to have it a long time.