Ultra-soft, lightweight, and quick-drying, this simple EMS Techwick Midweight Crew (on sale for $30) is made of 100 percent polyester. The fabric feels smooth and dry next to your skin, and the midweight thickness provides enough warmth for cool weather. The thumbhole feature prevents wind from blowing up your sleeves, but since the fabric isn't very stretchy, you can't push your sleeves up if you get hot. The material is antimicrobial, which resists stinkiness, plus it washes well — no shrinkage or pilling. This shirt is suitable for runs in the mid to upper 40s and is also a great choice if you don't want to spend a lot, or if merino wool bothers your skin.