Knights and their "clothes".

You know how soldiers today have on bullet proof vests and camouflage on in battle, well it connects over to the fact that knights wore armor to cover their toes to their teeth(exaggeration). Knights obviously wore armor not for fashion trends, but for their safety on the field so they would have a better chance of taking a hit. Some armor could weigh up to 50 to 60 pounds or more! Before you think that putting on armor makes you invincible, just know that people still got killed in battle even with armor covering their entire body to the point that  no skin was showing at all....except when  part of the armor was cut off.
To explain the armor, well it was just a full plate of armor, sometimes iron that covered your feet to your hair(if they had any). Well of course there was a way to breath inside the helmet or it wouldn't really be a good protection tool now would it. The helmet had little slit that could slide up and down for you to see and an airway for your nose and mouth.