When you think about wool, you probably picture an itchy sweater. In fact, wool comes in many different forms, and at its finest—Merino—it can even rival synthetic microfiber, especially when it comes to managing heat, sweat, and odor. There's a reason so much sportswear is made from the stuff—one company has even put the material's natural advantages into a shoe with the Giesswein Merino runner. Think running in wool shoes would make you hot, sweaty and stinky? Think again.