Elephant skin is wrinkled in appearance, with African elephants more wrinkled than Asian elephants. Wrinkles act as a cooling mechanism by increasing the skin’s surface area. The additional skin and wrinkles trap moisture, which then takes longer to evaporate. Therefore, wrinkles keep elephants cooler, for longer, than if they had smooth skin. Elephant skin can be up to 3.8 cm (1.5 in.) thick in certain places. However, the skin is sensitive to touch, detecting insects and changes in its environment. The combination of thick skin and a thin layer of fat beneath the skin enable the elephant to tolerate cold temperatures. Overall skin colouration for elephants is grey.