Relative humidity affects our daily lives, particularly what it does to our hair. As the concentration of water molecules in the air increases, transient hydrogen bonds form between the keratin proteins in hair, causing curls to form. A key factor is the dew point, the temperature at which the air becomes fully saturated with water vapor. Typical trends show that relative humidity (measured in %) decreases with temperature, although the correlation is not linear. These effects are shown in this Demonstration.