Our skin has not always been the same. Over the centuries, human skin has been gradually evolving in order to cope with the living environment. Paleontologists, people who study the history of life, have acknowledged the idea that human ancestors once possessed bodies covered in dense hair and rough skin. These two traits were important for human ancestors because they needed rough and hairy skin to protect them from the harsh winter, since the houses that they lived in back then were poor insulators against the bitter winter. As a result, the most obvious evolutionary adaptation is the roughness and the hairiness of skin.
It is believed that humans began shedding hair and losing the roughness of skin so that our bodies could adjust to the hot conditions and the need to lose body heat upon physical activity.
The picture below is a "skin cell gun" developed by Jörg C. Gerlach in 2008. It is an airbrush-like tool that is used to isolate and spray stem cells onto severly burned skin in order to heal the wounds faster. It is orginally created for the purpose of healing the wounded soldiers faster.