I have been trying to test what works well for me and have a questions on what everyone else is wearing. I live in Chicago and the temps have been in the teens - 30. I have tried to wear compression base layer and a synthetic top and wind break for hiking but my chest gets cool. I still sweat. I have also tried to wear my smartwool shirt and a synthetic shirt over that with my wind break and this works better but still cool on top. The rest of my body is warm so I do not have a problem with being too cold. What is everyone else doing for there tops.