They have two layers. In the summer you want to brush out the insulting undercoat, but leave the topcoat as it protects against sunlight. A shaved husky will overheat in the sun and can easily get skin cancer! It also doesn't grow back properly. The husky in this picture will never have a normal coat again as it has his fur ruined for the rest of his life.

There isn't any valid medical reason that requires to shave a husky entirely. Only people who don't understand how their coat work do it. It is basically animal abuse and it makes me sad every time I see this picture.