This shirt has the highest technological design that I have every seen.  It't the iPhone vs the tin can and a string.  Salomon uses different fabrics to match the natural movement patterns of the body.  The fabric has a magical cooling quality when water is applied on a hot day.  If you like a tight fit that feels like an invisable shirt then this is the shirt for you.

Link here.   http://www.salomon.com/us/product/exo-motion-zip-tee-m.html