This is an ideal shirt for a good hard workout at the gym or a hot day.  It's designed to wick sweat off your skin and keep you dry.  This can be worn under regular clothing as thermal clothing, layered on one of those days where one goes from extremely hot to extremely cold temperatures.

I pretty much live in this type of clothing all year around because it's very comfortable, stretchy, wicks sweat off the skin for comfort and it is designed to minimize body odor (not sure how they did THAT, but it works well).

I would recommend purchasing a size larger than usual because it is 100% cotton.