Figure 4. Increase in heat transfer due to hair, reported as a percentage h_hair/h_skin×100, as a function of ambient wind speed for different hair densities on smooth skin (A), and rough skin (B).

The heat transfer increase due to hair on our example elephant – which has a hair density of ∼650 hairs/m²– is ∼10% at low wind speed and decreases as the wind speed increases.