Proper skin care is important because our skin is the largest barrier against infection that we have. Keeping our skin healthy and moist helps keep this barrier strong. … This layer maintains skin's overall hydration and serves as our primary defense against the environment, so keeping it strong and healthy is critical. Protecting the body from environmental factors such as bacteria, fungus, viruses, allergens, water, and chemicals. regulating body temperature by sweating and adjusting blood flow to the skin. synthesizing vitamin D. … providing some protection against the sun's harmful ultraviolet rays via the skin protein melanin.