Icebreaker is brilliant15 January 2018I have a short sleeved version of this shirt and I have quite a lot of icebreaker shorts that are 150gsm, which are "summer" clothing. Icebreaker shirts are great allrounders. It definitely feels so much warmer than most fabrics when it's cold. But I also have been sweating in 35deg heat and the shirt has a wicking cooling effect. And the best things is it doesn't smell bad. You can definitely get a few days out of icebreaker gear without washing... Great for true adventuring. The only negative is the cost!