The skin on our lips has three to five cellular layers, compared to typical facial skin, which has up to 16 layers. The lips also lack the oil glands found in other parts of the skin. Therefore, as the weather gets colder and there is less humidity, the outdoor air combined with the indoor central heating can dehydrate our skin and cause lips to crack, peel and bleed - a condition known as cheilitis simplex.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/how-to-take-care-of-chapped-lips-this-winter