Fun Facts About Nails - as part of the expert series by GeoBeats. Our finger and toenails are made out of a hard material called keratin, which is the same material as our hair. The nails on a woman's hands and feet typically grow more slowly than the nails on a man's. In the warm summer, your nails will grow at a faster rate than they will in the cold winter. Typing with your nails will actually stimulate their growth, and has a similar effect to a nail massage. Only the area around the nails can sweat; the nail beds themselves are unable to do so.