In addition, skin is your first line of defense against infection. It fends off millions of germs, chemicals and other contaminants that are out to invade you. It helps regulate your body temperature and, of course, lets you touch and be touched, so you sense pain, feel pleasure, and express love.
Skin does one more genius thing: When the sun shines on it, your skin makes vitamin D3, the ultimate antiaging vitamin. It's essential for keeping your heart, bones, memory and blood pressure humming along.